The AM Forum

Hi everybody, as you some of you know, I'm looking for some better AM iron/gear than I have at the present time.  I also mentioned that I can't run more tha say 50w of carrier, if I don't want to risk the wrath of my neighbors, in my apartment building.  I'd like to thank everybody for the input on the Gonset G-76.  I will keep an eye out for one.

Here's some additional info.  Money is pretty tight for me at the present time (I'm paying off thousands in bills that were racked up during hard times a few years ago), and will be for some time (hence the reason why I'm stuck with some less than desirable gear at the present time).  So, I'm always on the lookout for ways to get decent AM gear on the cheap.  So, with that thought in mind, I may have to forego the G-76, and maybe get a transmitter, and use my ricebox rig as a receiver (until I can dig up the money for en economical [but NOT 100 lb weight!] receiver that does decent AM).

Today I saw on e-pay a couple of Johnson Challengers, going for OK prices (well under $200 at the present time).  Other than the fact that the Challenger is crystal controlled (which means scrounging for a VFO, or a box of rocks), and will do 40W on AM, I have no idea how good it is.  Is it a decent rig, or is it a dog?  Also, what are your thoughts on other cheap (just in cost - not performance) AM transmitters that will do the job (and no, I'm not afraid to open them up, and work on them, I do all of the servicing on my Swan and Kenwood tube rigs)?

73,
Ellen - AF9J

Hi Ellen,
I am assuming your QTH is still in WI as per QRZ.com.  If so, why don't you check into the Midwest Classic Radio Net (it meets on 3885 Saturday mornings and Rob WA9ZTY is the net control located in Marshall).  Use your rice box on AM and let it be known what sort of rig you are seeking and I bet you can come up with something closer and much less expensive than the Ebay route.  It is a friendly net and it is focused on use, sales and acquisition, and restoration of AM gear.

Hope to hear you on the net Saturday!

73, Rodger WQ9E

Hi Roger, 

Thanks for the info.  Yes, my QRZ address is current (I live in the MIlwaukee metro area).  I'll do that.  I was wondering if there was an AM net around here.  More than likely, I'll use the Swan.  I'm not happy about the overshoot in my FT-897D on transmit.  Even when running it at 20W of carrier, keying the mike, spikes power to about 30 Plus watts (it's only supposed to be rated for 25W of carrier), for a couple of tenths of a second, until the ALC kicks in.  No thanks!

73,
Ellen - AF9J

BTW, any ideas for a lower cost tranmitter?

For some reason the Johnson Challenger does not have much of a following. Can't say why, never had one, never knew anyone that had one.

Assuming you want to avoid paying the toll for the popular (and pricey) classics like Viking Valiant, Ranger, Heath DX-100, etc.

• Many people swear by the Heath DX-60 as a low-cost (eBay prices $80-$130), fun, easy to tinker-with AM rig:

http://oak.cats.ohiou.edu/~postr/bapix/DX60.htm (http://oak.cats.ohiou.edu/~postr/bapix/DX60.htm)

• Then there's a Multi Elmac AF-67 or AF-68 (eBay, about $120):

http://www.qsl.net/n9bor/Multi-Elmac.htm (http://www.qsl.net/n9bor/Multi-Elmac.htm)

You might be able to get a Heathkit Apache for near $150. Big rig, but can be made to sound very hi-fi. And the Globe Scout is a very sweet looking little transmitter and easy to tinker with. I'm sure we can think of a few more.

Yes...eBay is a LAST RESORT. Hamfests, AM swap nets, and "Buddy Pricing" is best.

http://cgi.ebay.com/Heathkit-DX-60B-Transmitter_W0QQitemZ120102757514QQcategoryZ4675QQrdZ1QQcmdZViewItem

for what its worth.....  klc

Keep an eye out at hamfests.  Ugly yet very serviceable transmitters are still around for reasonable prices.  I've passed up MANY $30 DX-100s.

Be careful when buying a DX-60/B, the function switch is a BIG problem and hard to find. There is an easy fix if your switch is still ok.
Gary...WZ1M

Oh yeah, I forgot to add:


I urge you to look into the National NC-300/303.  1960's built. Semi large, but fairly light, 60 lbs.  Stable, accurate sliderule tuning (rather than romantic but impulsive "where am I?" half-moon-dial tuning) and REALLY nice AM audio (although purists complain that it won't widen out to 16 kHz).  

I'll take all those $30 Dx-100's please!  I'll even pay shipping!

;)

Yeah but I think she wants a rig without zorched transformers, pots ripped out, rust, slime, and cat pee smell ;D

Yuppers! :)

I don't mind servicing my rigs, and even doing a few mods that are recommended (I do/did it on my Swan 270B, and Kenwood TS-820).  But I don't have the time, equipment, or finances to rebuild a rig from the ground up.  Also, while I've read of things that can be done to greatly improve the DX-100, I don't have the space for a 70-100lb transmitter.  Dimensionally I'd say sizewise - like a Johnson Ranger (but they sure have gotten expensive since I paid $150 for the one I briefly owned 12 years ago) would be best.  With some creative rearranging, maybe a Knight T-150 at the most sizewise.  I'd even consider a DX-35 or DX-40, if it's cheap.  Weightwise - I don't want to have the just about throw out my back to carry the thing (you ever try carrying a Fender Twin or Mesa Boogie tube guitar amp?  They push a 100 lbs!  That's one of the reasons why I don't have tube guitar amps anymore [besides you can get  cool sounding mega distortion out of some of today's solid state guitar amps]).

73,
Ellen - AF9J

Ya know Ellen... the Swan can be made to sound pretty good. Might you consider a linear for the ol' girl? That'll get ya into the 100 - 200 watt class as you research and decide on a good boatanchor.

I'd steer clear of the Challenger. IMHO it was EF Johnson's wost effort. TV tube final, screen modulated, crystal control - who needs it.

If size is an issue, I would echo what others have recommended - Multi-Elmac AF67 or AF68. 6146 final, built-in VFO. Many out there, decent prices, small size, separate power supply, they sound good on the air. They were known as the poor man's Johnson Ranger many years ago.

My 2 cents

Terry
W8EJO

Hi Julius & Terry,

Julius, actually for now, I have the Swan 270B set up for AM (It may not be DSB AM like my FT-897D, but it doesn't have the ALC overshoot problems my FT-897D has, when you first key the mic).  I'd prefer not use it long term for AM.  A friend of mine who is a Swan nut, told me some time ago, that while the 270B does OK AM (about 30W of carrier), it's kind of hard on the sweep tube that's used for a final.

Terry, thanks for the info on the Challenger.  It pretty much confirms some other info I read online about it - that it's not a very good rig.  Yeah, the Mult Elmac AF67 & AF68 have been added to my list of rigs to watch for.  The main issue with them, is finding a power supply that you don't have to majorly modify to supply the 22V the modulator drivers need, or for that matter, the dedicated power supply sold for these rigs (they're kind of hard to come by).

Another note to everyone - I'm willing to settle for crystal control for now (and then build or get a VFO later on), if it'll get me on AM sooner, with an OK transmitter, at a low cost.

73,
Ellen - AF9J

The trick to using the Swan on the air is to get everyone on the 'average' frequency, which lies between the high and low drift points. ;)

'JN is right on the money with the DX-100s. There are a lot of them out there, some better than others and some reasonably priced. I saw a nice one in a surplus shop in Portland OR when I was out there a while back, looked like new and could be had for around $50. Luckily I lacked the time and ability to deal with shipping.

Apaches show up often too, last one I saw was at Hopkinton last fall, for $100 including a pair of Aperex Bugle Boy EL34 modulators. Was in decent shape and worked.

Just be sure to eat your Wheaties before moving them....

Julius?? Hmmmm..................... ;)

Et tu, Brute?    :P

Another cool rig you might want to consider is the Heath Cheyenne, MT-1 transmitter. Although it requires an external power supply that shouldn't be that difficult to find or build. There's one on ebay now for $15.50 with 9 hours to go. There's also a matching receiver for it called the Comanche, MR-1.


(http://i5.ebayimg.com/04/i/000/94/06/1893_1.JPG)

Here's K2CQK's Heathkit Cheyenne and Comanche:

Hmmm,

Now THAT is interesting Pete.  I put it on my e-bay watch list.  All it needs, is a power supply.  The band switching on it looks like the same type of switching as the HG-10B VFO I used with my HW-16 as a Novice.  Oh, BTW, I also noticed Knight T-60 on e-bay, going for $60 on e-bay.  Anybody have any thoughts on it?

Oh yeah Todd, about the Swan - drift?  You must mean the 350 or the 500 ;)  MY 270B is stable after about a 15 minute warmup.  It also has killer audio. :)  You guys are great!  Thanks for all of the suggestions!  Keep em coming!

73,
Ellen - AF9J

The CHeyenne is basically a DX-60 with VFO but minus the power supply.  Single 6146 screen mudulated.  One of the Heathkit HP32 power supplies (intended for the SB102 etc) work Fine Business.  The normal DX-60 mods apply to this xmitter as well.  It's harder to work on than the DX-60, but has the advantage of having a nice stable VFO built in.

The matching receiver is essentially junk and not worth considering for AM use..

I have a watch on it as we speak. With 1 hr 50min to go, the high bid is just under $23.  Unless somebody snipes me in the last minutes, I could pick this up dirt cheap.  I also have a watch on a DX-60B on e-bay that's in Sheboygan (about 40 miles north of here).  That rig, I could pick up myself, saving on shipping.

Both the Cheyenne and the the DX-60B are a horse a piece:

Cheyenne 

Good - already has a VFO, chance to get it dirt cheap

Bad - need to scrounge up a power supply for it, harder to work on than DX-60B, since it's a 50s rig; it uses the "plain" 6146, instead of later and much more plentiful 6146W (which I retubed my Kenwood TS-820 with last year), oftentimes earlier Heathkits don't neutralize properly with the 6146W.

DX-60B

Good - built-in power supply, possibility of picking one up nearby; saving on shipping, easier to work on than Cheyenne, the one nearby has been refurbished in recent years
 
Bad - no VFO (HG-10B is getting harder to find, and expensive to boot).

73,
Ellen - AF9J

Yehaaa!  I just won the Cheyenne!  My winning bid was $42.11.  Now I have to wait for a shipping cost on it.  Well, I'd better get some sleep.  BTW, anybody know what the mic impedance is?  I hate the mic that's coming with the rig.  Strangely enough, I prefer either hand mics, or and Astatic D-104 like I had back in 1995 (I assume it would have to be high impedance).

73,
Ellen - AF9J

 here ya go              http://bama.edebris.com/manuals/heath/mt-1/

    "  Microphones

Since mobile operation demands that properly shaped audio response be
employed, a vary carefully designed ceramic microphone is included with the
MT-1 "Cheyenne" Mobile Transmitter. This is to insure very effective
modulation with plenty of "punch". The microphone serves to suppress all but
the upper middle range of the voice frequencies and the audio system, as
described above, is designed around this response. If other microphones are
used, it may be necessary to alter the circuit components and the modulator
for best results. In any case, the microphone should be a high impedance type
and preferably ceramic, since crystal or carbon microphones can be damaged by
the hot sun to which they are often subjected in mobile operation.   "

Wheeee! Congrats. Now the real fun begins. There are plenty of Heathkit HP-23 power supplies available on eBay for bargain prices, but the HP-20 used by the Cheyenne seems rare as hens teeth.

Googling around, I see that Cheyenne owners were wrestling with the problem a decade ago:

>I realized that the cheyene requires 600V and the hp-23 provides 800V.
>Any ideas on how to make these work together?  Thanks for reading.

Even if the Cheyenne has a 6146 (or two) in it (as do the radios that
originally used the HP23-series supplies), part of the problem may be that
its final tank circuit was designed for best operation at the lower
voltage. No-load voltage of the HP23 may be as high as 900 volts
(especially on today's high AC line voltages) and you'd have to carefully
check everything in the Cheyenne's high B+ line to make sure it can handle
at least that much. Perhaps the final's screen supply is via a dropping
resistor instead of directly from the low B+? In that case, you'd want to
change that, either the dropping resistor itself or shifting it over to the
LV B+ supply.

Then, too, look at the original low B+ requirement: is it actually what the
HP23 provides or somewhat lower (such as 200V original vs the switchable
275/350 from the HP23B, or 250/300 from the older HP23)?

And how about the bias supply? And any relays in the Cheyenne? Does the
Cheyenne have any relays running from the bias supply, and thus capable of
exceeding the HP23/23B's bias supply rating? You're probably OK on the
filament supply current requirement but it wouldn't hurt to check that out,
too.

You need to go through each and every one of these if you don't want to
cook something in the Cheyenne or power supply. You *could* use a variac on
the AC supply except that'd probably reduce the filament voltage and maybe
the bias voltage too much. Then again, perhaps you could find a happy
compromise, such as reducing the AC input voltage to where the filament
voltage dropped from a nominal 6.3 to only 5.5 or so (or 12.6 to 11.0),
which is a drop of about 13% which would drop the HV from a nominal 820 to
715, not too bad (of course, the LV will drop the same). No variac? Try a
filament transformer wired as a "bucking" transformer; I do that for my
shop lights now and that's caused my lights to last a lot longer than the
usual 3 months or so than on the full AC line voltage.[/i]

(PS: The Electrovoice "banana" mike: seem to recall it was ceramic, hi-Z.)

Yea, what he said!!
I had one of the receivers it is a real P.O.S. Too narrow of bandwidth (fixed crystal lattice filter) Piss poor AGC action, and horrible dynamic range. You would have to reinvent the wheel to make it tollerable for serious AM. I got rid of mine quickly.

                                                    The Slab Bacon
 

I ran a Cheyenne just fine with an HP32 power supply.  You hafta match the fil voltage of the HP32 with whatever the CHeyenne is wired for (either will do 6 or 12 V filaments).  Runs the relay just fine (the Cheyenne, as a bonus, includes an internal T/R relay!).  Last, you hafta adjust the bias in the HP32 to match the demands of the Cheyenne (or perhaps the Cheyenne has an internal biass adjust, I don't remember now).

6146Ws or 6146Bs work fine, in my experience, with the CHeyenne.

Don't expect miracles out of this little rig.  The loading is fixed and the audio circuit could be improved.  But it's a cute little package and works very, very well for what it is.

I believe it has a high impedance mike input and there's plenty of mic gain available for just about any mike you care to throw on it.

Hi John,

Thanks for the info.  It's nice to know that I won't ahve to build up a T/R relay.  ALso, so it's a basic rig - no big deal to me.  Als long is it has decent performance, bells & whistles are secondary to me.  BTW, isn't the HP-23 supply used as part of the HP-32 (so isn't the HP-23 what I really need)?  Doesn't it's high voltage feed have to be lowered from 820V down to 600V?

Also, I have a dumb question.  It's good to know that 6146Ws can be used in the Cheyenne (especially since plain jane 6146s are pretty hard to come by).  Sooner or later the final will go out.  I have a set of chinese 6146Ws sitting around.  Orignally I bought them last year, to replace the Phillips 6146Bs that were going soft in my Kenwood TS-820.  When I used them in my TS-820, they flashed over as soon as I turned on the heaters, giving me the opportunity to open up the rig, and replace some burned out resistors on the High Voltage board, some iffy resisitors on the Finals Board, and put in some NOS PHillips/JAN milspec 6146Ws (those worked fine).  Kenwood hybrids run about 900V at the plate, so it's obvious that the Chinese tubes didn't take to kindly to the higher voltage that Kenwood hybrids run at.  But since the Heathkits run at lower plate voltages, will my Chinese 6146Ws (which are just sitting around collecting dust) be usable in the Cheyenne?

73,
Ellen - AF9J

P.S. - cute dog in your avatar (I grew up with dogs, and am a dog lover to this day).  American Pit Bull Terrier, or American Staffordshire Terrier?

Congrats on the win, Ellen!  :D

One thing to keep in mind with the HP-23 supplies is that sometimes the Collins users snag them as replacements for the 516F-2 used with the S-Line and KWM-2. So you might want to bid later instead of sooner, so as not to tip your hand too early. There are plenty of them out there, so you should be able to get one without a lot of trouble. Maybe even post a want ad in the classifieds here?

If those Chinese 6146s work out for you, I have a few NOS ones here that you are welcome to. Probably some good RCA pulls, too.

With the smaller rig, you'll be able to run low power AM in good conditions, and just add a decent amp for the evening hand-to-hand combat on 75m.

Good luck with the new project.

Hi Todd,

Thanks for the offer of tubes.  :)  I shouldn't need any at the moment.  Like I said, I think part of the reason the Chinese 6146s give Kenwood hybrids users so much grief (don't EVER use them in a Kenwood hybrid - most of us who have, have ended up having to fix something), is because the 6146s are run at higher voltages (900V at the plates) than they are typically run at.  I have a watch out on 2, HP-23s on e-pay.  Oh, and placing a wanted to buy in the Classfieds section of the Forum for an HP-23 (or an outside chance HP-20) power supply is a good idea.  Thanks for the suggestion. :)

73,

Also watch for the UT-1 which was the original power supply sold for the Cheyenne, also rare but they are out there.  The supplies built for the WRL/Galaxy III and V transceivers are nice supplies which will also work and are often available cheap.  These power supplies would be oversized for the Cheyenne since they were built for higher power transceivers but the voltage should be right since the Galaxy rigs used sweep tube finals.  The Drake AC-3/4 supplies would also be okay but the price on these has really sky rocketed in the last couple of years.

Rodger WQ9E

I have a question about the HP-23 power supplies.  What's a decent price for one?  I just put a watch on an HP-23A, and an HP-23B on e-bay, and both of them have "Buy it Now" prices of around $75.  Is this too much?  Also, which is more suitable the HP-23A, or the HP-23B?  Oh yeah, there's also another one that's I'm watching that has 2 or 3 days to go.  The high bid is at $32, and it not only has the enclosure, but the buit-in SB-600 speaker.

73,
Ellen -AF9J 

Hi Roger,

Once again thanks for the info.  How much are thu supplies for the Galaxy III and Galaxy V typically going for?  Also, isn't the UT-1 the DC supply for the Cheyenne?  Is the HP-13 DC-supply adequate (In a roundabout way, I could use it, and my Astron RS-35A to power the Cheyenne).

Slaving away at work,
Ellen - AF9J

Hi Ellen,

The MT-1 is the mobile supply I believe, the UT-1 was named the "utility supply" and was designed for the Cheyenne for fixed station use but was supposed to be suitable for other similar rigs.  I have one that someone neatly built in to a Cheyenne/Commanche sized case complete with a speaker and analog clock timer in the front that I use with my Heath "mobile twins". 

I saw one of the Galaxy supplies with speaker go for about $35 on ebay 2 months ago.  I meant to bid on it so I could use the speaker with my Galaxy R-530 receiver but I forgot to bid in time.  Again, I imagine you can "scare up" a suitable power supply on the AM net Saturday morning as any of the power supplies designed for a Swan, National, WRL/Galaxy, Drake, or Heathkit tube type rig should work though the HP-23X supplies will have a higher than intended plate voltage. I have never used any of the DC to HV mobile supplies so someone else would need to comment on the reliability of these.

Congratulations on the Cheyenne!  You should find the matching mobile receiver now so you will have a pair of units.  If it has the original mic connector on the side it is the same connector used for old Motorola units.  If you don't have the power supply cable I believe that Leeds electronics (they are on the web) should have the connectors; these are either 9 or 11 pin "octal type" connectors if I remember correctly.  If you need to make up a power cable, heat shrink tubing is available in rolls so you can use a single long piece to cover the wires and make a neat original looking cable.

73, Rodger WQ9E

Thanks!  Actually he's a purebred Boxer.

Don't sweat it with the tubes.  I'd use American tubes as they are more likely to take the slightly higher voltage from the HP23 (or 32, or whatever it is).  My combo worked just fine.   

73 John

Average price to get an HP-23A or B(a decent one) is probably around 50 to 60 bucks at most hamfests.
Of course you will pay more on "epay",--so $75 is about right.
Problem is,--you have no way of knowing how good the filter caps are in those supplys, as they
are now getting "old", so you might have to get new electrolytics.

I have found that most guys who are selling an HW-101, or SB-101 want almost as much for the HP-23
as they do the tranceiver.
Its like when buying a DX-40 or DX-60,--the matching VFO will cost you as much if not more than the
the transmitter itself.(priced xtals lately?)

                                                       73, K1MVP
P.S.,
They do make a nice power supply,--and they put out about 700volts DC, for high voltage and 275 to
300 volts, low volts --you should be able to feed either a single 6146 or a pair of them, with no problem.



 

The point about electrolytics is a good one although careful shopping at Mouser or Digikey will yield fairly low cost replacements.  The shipping on the HP-23 will also be significant if it is traveling a long distance.  I agree that the $75 ebay price is probably a good indication of market as these have gone up in price, especially since they can be made to work with Collins gear.   A couple of years ago I was at the Peoria, IL fest and spotted an SB-600 with an HP-23B inside sitting on top of an HW-101.  I asked how much for the power supply/speaker and the reply was thirty dollars so cash exchanged hands.  I picked up the SB-600/HP-23b and started walking away when the seller yelled, "Hey, you forgot your transceiver" so it turned out to be a very inexpensive power supply.  This was the same fest where I spotted one of the more infamous ebay sellers literally tossing several Collins rigs into the back of his SUV.  Even though they were in nice shape (as they would be described in later ads) they wouldn't be by the time they made it back east bouncing around with no protection.

Rodger WQ9E

Help!!!  I have a question.  I got back from my usual helping out at the animal shelter I do every Sunday, and I took a look on e-bay, and put in a bid on an HP-23 power supply.  Now here's the kicker.  I went to the Heathkit Virtual Museum, and took a look at the Cheyenne specs.  It turns out that the mobile power supply is supposed to be an HT-10.  Here's the URL:

  http://www.heathkit-museum.com/ham/hvmmt-1.shtml 

Read the section that's titled "Power Packed Performance at Low Cost"

I looked on e-bay, and wouldn't you know it, one of the e-bay stores has an HP-10 for about $40!  I'm stuck with my bidding on the HP-23 (It has 2 hours to go).  But I have a question.  If I lose the bidding on the HP-23, is it possible to use the HP-10 with my Cheyenne, and hook up my Astron RS-35A (25 amps continuous, 35 amps intemittent), 13.8V regulated power supply to power up the Cheyenne, or am I barking up the wrong tree, with a cheezy idea? 

73,
Ellen - AF9J

http://www.heathkit-museum.com/ham/hvmhp-10.shtml (http://www.heathkit-museum.com/ham/hvmhp-10.shtml)

Not a cheesy idea. May be a bit kluge-y, i.e. having yer Astron supply tied up heating transistors in the HP-10.

I can live with kluged together.  But it's looking like it's going to be a moot point.  With 35 minutes left, I still have the high bid on the HP-23A (a little under $26).  And, I set my bid limit at $73.  OH well.  I wish I'd know about it sooner.

Ellen - AF9J

Well,  I was right. It was a moot point.  I won the Auction at $46 (plus another $20 for shipping, for a total of $66).  So, I guess I'll be modifying an HP-23A supply.

Ellen - AF9J

P.S. - now I just need to get my hands on a receiver.  e-pay's getting kind of pricey.  So, I'll go to the MARA hamfest in Madison, WI (I passed my General at this hamfest, in 1986, and Madison is the home of my old alma mater, the Univ. of WI), and see if I can get something cheaper there.  I'm open to any input on some decent AM receivers.  My criteria - can't weigh more than 40 pounds, and preferably less than 18in wide.

Based on some advice I have received here, going small like this, if you want to stay in with tubes, I suspect you would have a hard time doing smaller/lighter than a Drake 2-A or a Drake R-4B and still do decent with AM reception, and many like (and don't like) newer Hammarlund HQ's like HQ-100, HQ-110, HQ-145, HQ-160.  But I'm no expert (I just play one on TV).

If you are will to go Solid-State, I have some affordable suggestions, like Drake SW-8, Drake SW-2, Palstar R-30 (maybe not so affordable), and perhaps a kenwood R-1000.

Tarnation! You've just ruled out all the good rigs.  ;D

Hmmm. Under 40 lbs. That's tough. OK. How about the Drake 2B? Not exactly renowned as an AM rig, but all the ingredients for reasonable AM fidelity are there. (When I was kid I used to SWL the local AM old buzzards, and they all thought the 2B was just dandy for AM) And it shore is a good looker, and approx. the same size as the GriefKit, er..I mean HeathKit.

http://www.universal-radio.com/used/u287lrg.jpg (http://www.universal-radio.com/used/u287lrg.jpg)

The HP-23 is designed for SSB rigs but..
This is just some info on the HP-23 PS conversion when you want lower voltage, more current and more regulation on the HV. As discussed, the full wave doubler can be converted to a bridge. If you want to get fancy, add a choke as shown. Then you can get some sweet regulation for AM.

The mobile supply can be converted as well. You will go from 820 VDC at 250 mA peak to 400 VDC at a solid 300 - 400 mA. I have used this approach on Command sets in the car with modulator handled as well.

73's Mike WU2D

Kenwood R-599A or D series is a great receiver. Great for AM/CW/SSB/FM. You can even switch the receiver selectivity from 500 Hz to 25 KHz. Covers the amateur bands but not WARC ranges. Uses some of the same or similar receiver circuitry of the 520 and 820.

(http://i18.ebayimg.com/07/i/000/95/df/4f1f_12.JPG)

The Drake R-4 series are small too. Some can be modded for good AM bandwidths. I had an R-4B. Even though the widest bandwidth was 4.8 kHz, judicious use of the passband tuning could yield decent audio.

Agree completely. I had an early R-4 next to my bed for years and used it a lot when working around the house upstairs. Stable, lastest/greatest tube technology, decent sound with a decent speaker.

IMHO, Drake 4 Line gear is one of the best, if not the best bargains out there today. Prices are sloooowly catching up, but they've never received the credit they deserve aside from the TR-6.

The 599 twins are nice for the price, but the transmitter doesn't have 160.

I believe the 2-A has the advantage of 4.8kc bandwidth over the 2-B's max of 3.6kc.  At least that was the advice I have received.

I don't recall ever having any Drake rig that I liked other than for use on SSB. I've had the B line, C line, TR-4C, 2-B, 2-C, 3 TR-6's including one with all the 2 meter boxes, and I got rid of them all over the years. None of them seemed to sound great on AM in their "stock" existence. Now, I'm Drake free, and don't miss any of them.

Problem with a lot of the small tube receivers are they are either "broad as a barn door" ("swl" rigs, like Hallicrafters) or narrowly filtered (Drake), with AM as an afterthought. However, if you are planning on working 75M at night, the broad rigs won't cut it. Best is to find something that gives you the option of both "widebody" and "battle" modes.

I've heard of a relatively simple mod that would widen the 4.8 kc  bandwidth on the R-4/A/B to around 6 kc. Anyone have this?

Drake sold a 6 KHz filter. I put on in my TR7A. They also made one for the 4 series.

That was for the C series. The low/last IF in the A/B series was LC.

Thanks for the schematic with the recommended mods to the power supply Mike!!  :)

73,
Ellen - AF9J

Thanks for some of the receiver info everybody.  :)   I used to have an R4B (and T4XC) back in the late 80s & early 90s.  I remember the widest bandwidth being 4.5 kHz. It was a good rig.  Nowadays I kind of regret selling it. There was a good point made (I'm paraphrasing) about being caught between a rock and hard place with a smaller receiver, in that you're either stuck with a very wide bandwidth, or one that's too narrow for decent audio. OK, with those thoughts in mind what would all of you recommend instead (keeping in mind I cannot afford 75A-4, or don't have space for an R-390)?  Oh, and it makes no difference to me if it's solid state, as long as it performs OK on AM.

73,
Ellen - AF9J

My vote for the receiver of choice for the new-yet-serious AMer (as opposed to the gonzo purist who cannot tolerate anything short of an R390 or Racal) is the National NC300 or 303. Beg, borrow, steal, or contrive to get a look at one in the flesh. Very user friendly, not skittish, presumptuous, or pretentiously gimmicky. Spend a few moments getting to know this fella. Real pleasant audio. Honest tuning display. Sensitive even on 10 meters. And best of all, not a backbreaker to move.

http://www.qsl.net/ab0cw/nc303.htm

Hmmmm,

I took a look at the link. It looks cool. OK, I'll put it on my list.  Thanks for the info. :)

73,
Ellen - AF9J

The LC filtering in the R4/A/B has a fairly gentle roll-off (4.8 KC at 6 DB down and 20 KC at 60 DB down) making the 4.8kc BW position totally acceptable for AM. I use mine for AM all the time & it sounds good to me. Not Hi-Fi but good.

Terry
W8EJO

A good working R390A receiver is hard to beat!

Ellen,

The T-60 and the DX-60 and the Challenger were all intended as "entry level" radios for Novice use, with some offering 6 Meter capabilities for those who upgraded to Technician.

They are basic, simple rigs, screen modulated and crystal controlled: they're easy to work on and are fine for ragchewing if the band is quiet, but you'll probably want higher power at some point.

For now, I recommend you borrow one from your Elmer or another club member, and use it until you can afford one of the "big iron" rigs: there are lots of them sitting on shelves that their owners just keep for nostalgia. You can put out the word at your local club, and there's always your friendly local BBS  ;).

HTH. YMMV.

73, Bill W1AC

Yea!! What he said! A good 390A Is definately tough to beat, good natured, and easy to use. I've had one (or more) for more the past 20 years! It is still the benchmark that I use to judge ALL other receivers by. 
 
                                     the Slab Bacon

But it's BIG, thus not meeting her requirements.

well can I interest you in a Racal RA 6830 1/2 rack 20 LBs. not cheap though but work very well. (Shameless plug, I build them and sell one a year or so)
Or you could check out the Cubic CDR3280 on epay $4K buy it now still in production.

That would be an interesting dichotomy - a $4000 receiver paired with a $40 transmitter! No chance of being an alligator.

VERY TRUE!

Ellen - AF9J

I'm surprised no one has mentioned the BC 348. Not too versatile, but if acquired for cheap, it can be a serviceable AM recvr.

Also of interest: the NC-270. (Often known as "Cosmic Blue" due to its striking coloration) Selectivity from 600 cycles to 5 Kc. Dimensions: 8 5/8" high---15 5/8" wide---9" deep. Shipping Weight 28 lbs.

(http://www.io.com/~nielw/nat_list/nc270.jpg)

Since we're taking about AM receivers - What's the best IF bandwidth and rolloff for AM.  The filter in my SSB rig (Swan 500) might be a bit narrow, but the phase distortion is a real killer.

If I knew what works best on AM, I'd build a active filter to AMize my rig.

Tom, AB1GX

There is no one best bandwidth for AM. A selection of bandwidths or continuously variable bandwidth is preferred. It all depends on the amount of QRM/band congestion. If the band is relatively uncrowded, a bandwidth 10 kHz out to 16 kHz or so are quite nice for real "hi-fi" audio. Once things get more crowded 6-9 kHz is more suitable. Under very crowded conditions or if you are working a real weak one, less than 6 kHz is often needed. Anything less than about 4 kHz really starts to kill the audio and you would be better off copying in the SSB mode.

But, if I had to go with just one, it would be 7 kHz. It's narrow enough (especially if the skirts are sharp) to kill most QRM, but wide enough to allow decent audio.

Then I would put in a solid recommendation for a Drake SW-8.  It has an AM-sync detector as well.  But an external speaker will do you better, even though the internal one is not bad.

http://www.eham.net/reviews/detail/600 (http://www.eham.net/reviews/detail/600)

I have done a lot of reading/asking about receivers (what to consider buying), and while I have yet to be able to operate one in person, this is one that I would suggest it is one of the most universally appreciated ham receivers.

If you want small size and weight and great performance on AM and SSB, the Davco DR-30 is hard to beat.

(http://www.qsl.net/la5ki/org/da/dr30.jpg)

Now THAT looks cool!  I just did a Google on the DR-30.  It's too bad that they're so rare.  It looks very much like what I'd like to have.  BTW, the NC-270 listed above is OK too.  Also, thanks for the info on a good all around bandwidth (7 kHz - if you can't get your hands on crystal filters or other bandwidth changing devices).

73,
Ellen - AF9J

Another possibility is something in the Heathkit SB-300 line since you do have a Heathkit transmitter.  I have a 301 and a 303 and they both do a good job on AM (I have the AM filter in both of these).  All of these models are fairly light and compact and you can choose tubes (300,301) or transistorized (303).  The Allied AX-190 (solid state Trio/Kenwood sourced) and the A-2516 (tube type and a bit less common) are also compact, light weight models.  I picked up the closely related Trio JR-310 receiver at a hamfest last year and it has the nicest tuning feel of any receiver I own (well actually a close second to the KP-81 but it weighs about 80 pounds without its matching power supply/speaker).

Rodger WQ9E

Slab Bacon has some interesting comments on the HQ-110. These are relatively lightweight and easy to hurl around the shack.

http://www.amwindow.org/tech/htm/slabrxreview.htm (http://www.amwindow.org/tech/htm/slabrxreview.htm)

Hi Joe & Roger,

The Trio JR-310 - I took a look at it on the Rigpix website.  It looks similar to a TS-520S I birefly owned in college in 1986.  I can believe that it's tuning feel is good.  I have a TS-820 (the very first year edition of the 820 series [mine has just the analog dial display, since the digital display was only avialable as an option, when it was made in 1976]), and it has a fantastic, silky smooth feel to its tuning.  What's the bandwidth of it, in AM mode?

The HQ-110 - I had one back in 1995, when I made my brief foray into AM  back then (want to get cheased off of AM? - live in an area that has Channel 2, and marginal reception of it at best.  can you say TVI issues in the making? sure you can, I knew you could!).  It's an OK receiver in its stock form. I agree with Slab Bacon that the mods that can be made to it, make it much better. But nevertheless, in stock form, it is, in my personal experience, a pretty useable receiver for AM.

All of you are great!!  Thanks so much for the info and suggestions. They sure beat me having to reinvent the wheel, and find out the hard way!

73,
Ellen - AF9J

Speaking of my "receiver road test" article, as soon as I get a chance to type it up and send it to Steve, I have 5 or 6 more receivers to add to it. (hamfesting has been good to me the last 2 years)
                                            the Slab Bacon

IIRC, the TS-820 did not have an AM mode selection.

That KP-81 is a cool looking radio and quite rare in my experience. I've only ever laid eyes on one.

I agree Steve,

No, when I cited my TS-820, I meant for physical feel on the main tuning, compared to the Trio JR-310.  Yes, it's just an SSB & CW rig. BTW, Kenwood did make AM versions of the TS-820S, and the TS-830S.  They were called the TS-820M, and the TS-830M.  They were only sold overseas (mainly in Europe).  I'm a moderator on the Yahoo Kenwood hybrids group, and occasionally the members will pick up one of these up in a e-bay auction.  These rigs did about 20-25W of carrier, in SSB with carrier mode.

73,
Ellen - AF9J

I have a KP81 in pieces and I'd love a skizmatic for it with parts values.  I have a manual (somewhere) but the parts list is missing.  Mine had a bad case of acne and I repainted the front panel black wrinkle, but it needs to be re-assembled.

So many projects, so little time...

BOY!! do I know that feeling!!

And, err, it figgers, John if anyone would have one it would be you. I have also never seen one in the flesh.
                                                     The Slab Bacon

Actually the AM addition, is fairly simple to these rigs (several discrete components, 2 or 3 transistors, relay). The more difficult part might be to find the 6 KHz AM filter to fit in there.

I still love my Kenwood 599 Twins for all purpose AM and SSB operation. Nice looking, work well, and can hold either one with one hand.

Cool. I'll have to keep a look out for one. I've always liked the 520's and 820's, and they are solid performers. But I never got one due to the lack of AM. Made my first contact as a JN on a TS-520.

Kenwood also made a receiver called the R-820 (roughly matched the TS-820 on styling) that did have an AM mode. I've never seen one, but ya never know.

I'll get pounded for this........

Rat Shaft dx 302

An allignment, a little work on the audio,  maybee widen/add more appropriate  filters... 

Why??  General coverage, digi readout, its got a mute, tape out, code practive oscillator (really), external speaker connector, its stable, light wt, physically medium sized, parts are identifiable, and for the most part replaceable... 120v /12v  ... and its cheep  ..... pick them up for $70 ish --------------- ( also,the Fine RatShaft name,  )


klc

Hi Johnny Novice,

I don't think that there is a schematic with parts values for the KP-81.  I got a complete unit, a modified unit (loctals in front end replaced with miniatures) and a parts unit and all 3 came with their manuals.  None of the manuals have parts values though they do have a note that a complete manual with parts values will be mailed out when it is completed; I doubt the second manual ever materialized.  I do have a "translation" of a letter on alignment of the KP-81 that Karl Pierson wrote to the owner and I will be happy to make a copy of this for you.

Your KP-81 is well worth restoring, it is a very nice AM and CW receiver.  Be prepared for fun when you recap the front end however.  The two IF decks unplug for easy access but to get to the front end you will have to remove the coil catacomb to release the RF sub-chassis.  Then it appears that originally everything was wired and then the sockets and terminal strips were riveted into place.  I had to use a long nose soldering iron, several different pairs of needle nose pliers, and a lot of patience (mixed with a few curses) to repair this part of the receiver.

One of my manuals has some hand written values added by a previous owner but I doubt that they are complete and I didn't check the accuracy as I went by the value of the installed components.  The same owner also included a time sheet for the amount of time he spent mowing the local graveyard so at least he did document everything.

73, Rodger WQ9E

The KP-81 is the AM heavy-weight receiver champion for sure!

TNX, Rodger.  Yeah, I pulled the front end and IF modules out, recapped /em, but the IF module is dead for some reason.  It's all in a box up in my attic now.  Would appreciate any info you have!

I don't have the matching amp/speaker.  If you have a spare, I'd definitely be interested in that as well!  I do have a spare S-meter that I recently found at a hamfest though  ;D

It's a contender but I think some others weigh more. The SP-200 RX section alone weighs around 70 pounds and the separate power supply is another 50 or so. The R-390A weighs 95 pounds. Then there some beast the FRR-9 (IIRC) which weighs several hundred!!!

Yeah, but...

(http://img95.imageshack.us/img95/5939/pumpyouwr3.jpg)

We have a couple of members in the Kenwood Hybrids group who have R-820s.  According to them they're pretty good.  They can also be slaved up to the TS-820S for split frequency work.  I like my TS-820. It's very well made.  The only problem with the 820 series, is the digital display unit.  It's mounted relatively close to the finals enclosure, and as a result, is subjected to heat.  The board contacts oftentimes have to be cleaned, and the mounting/ground screws retightened. I will say this though.  The dial display does work quite well freqencywise.  It is a National HRO-type dial with two geared/nested dials, and slots next to each 10 kHz digit, that show the hundreds number.  Frequency resolution is 1 kHz.  Oh, and this same mechanical dial is also on the entire 820 series, and a variation of it is on the 830 series.  If you'd like, I can put in a WTB for an 820M or 830M on the group.  It's up to you.

Ellen - AF9J

Although I have not actually weighed mine, according to the manual the combination of the receiver and its power supply total 120 pounds after uncrating.  I have a couple of SP-200's and their power supplies so perhaps I should put one on each end of my daughter's teeter totter to empirically determine the heavy weight champion.  I do know that either are much easier to move than my Johnson Tbolt or Viking 500 modulator/power supply.  If either of those rigs loses a power transformer it will be replaced by the lighter hypersil version!  For a real workout, carry an HP 524C counter up a flight of stairs; I don't know how heavy it is but it sure is awkward.

JN, unfortunately I don't have a spare power supply speaker or you would be welcome to it.  The "complete" receiver which I have restored came with a speaker/power supply and the modified receiver came with a speaker/power supply less one of the transformers.  I will try to restore that one at some point just to see how well the modification to miniature tubes was done.  At least the sheet metal work to install the sockets is very well done so hopefully it is also done well electrically.  The parts unit is missing the sliding coil catacomb and the entire front end assembly so it is basically an IF/detector but I am thinking of using it as the basis for a homebrew receiver since it has such nice tuning capacitors and a very nice IF selectivity response.

One of the first things I would suspect on your IF units is a bad loctal tube socket.  I had to replace a couple of the socket contacts in the restored receiver and I have had to do the same operation on one of the RME receivers I own; at least it is easy to do. 

Let me know what sort of manual or schematic you already have for your receiver and I will make and send copies of any additional information that I have with mine.  This is one of those receivers I never expected to find but I was helping the owner move some of his equipment from his pickup to his table when I spotted these so kindness is rewarded.  It is well worth fixing yours since the mechanical and electronic performance of the KP-81 is very nice.

Rodger WQ9E

Ellen,

I have the TS-820/R-820 pair and I agree the R-820 is a very good receiver and sounds great on AM-unfortunately my TS-820 is the "S" version so no AM on it.  I have been toying with the idea of doing an article for Electric Radio comparing the TS/R 820 combo to the Drake TR7/R7 combo; since these are transceiver/receiver pairs they can be called cousins instead of twins.  In short the Drake receiver performance is better for weak signals and particularly when QRM is heavy but the Kenwood pair is quite attractive and frequency stability is better unless you pair an RV-75 (rare and expensive) with the Drakes.  And of course the TR-7 transmits AM.

My TS-820S was a $75 hamfest buy because of the flaky digital display.  I got copies of all the service bulletins for the display and performed the recommended procedures and the display problems were different but still flaky.  Over the next couple of weeks I would work on this in my spare time but still found it would flake out during different parts of the warm-up cycle.  I finally decided on drastic action (that I DO NOT recommend others follow).  I took my Harbor Freight heat gun and reflowed the solder connections  and it has worked perfectly since; one of the few times that losing one's patience leads to a desirable result.  By that point I would have preferred a completely dead digital display to one that was intermittent since the mechanical readout is so nice on the 820 rigs.

73, Rodger WQ9E

Here's another thought Steve & Roger,

If either of you are still interested in a tube Kenwood with AM capability (besides the Twins), there is the TS-900.  I've read a few reviews of it on e-ham, by some hams who have used it for AM, and they said it's an OK rig for AM.  The only downer about it, is that it's relatively rare (but much more common than the TS-820M, or 830M), and it uses sweep tubes for finals. Also, unlike the Kenwood hybrids, it uses an outboard power supply.  It's a cool looking rig.  You know how the earlier Twins have what looks like brushed chrome enclosures?  The TS-900's enclosure, looks like copper.

BTW Roger, when I got my TS-820 (the very first year version of this series - the digital display was only available as an option, and mine didn't have it installed), I also had a choice of getting an 820S.  I just didn't want to screw around with the display.  I find the dial mechanism (which is pretty much like the one on the Twins), to be just fine.  You did the best method for dealing with the display problem, resoldering things.

73,
Ellen - AF9J

My all time gonad buster was the RCA AR-88 I had. Don't know the weight but I always dreaded moving it.  Big, awkward & extremely heavy.

My Valiant seemed like a lightweight in comparison.

The National FRR-59/WRR-2 is well over 200 pounds.  The TMC DDR-5 is a synthesized receiver in a 6' rack and is, IIRC, almost a thousand pounds.

HUZ knows firsthand about the weight of the FRR-59 - he helped me move it from my pickup to the table at Dayton one year  ;D

Yea, my back still hurts!!

I may be in touch on the TS820/830M Ellen. Any idea what they go for?

Not really sure Steve.  Probably similiar in price to the 820S & 830S (in other words about 260-400 dollars, depending upon the condition).

Ellen - AF9J