The AM Forum

Tell me about it!!  I'm damn near 70 years old and I still buy things that give me buyers remorse for about the first 24 hours.

I just purchased an ART-13 that I want to use in my car.  I'm Freaking NUTS  ::) ::) ::) ::) ::) ::) ::) ::) ::) ::)  

25 watts on AM will not keep you in the games on 160/75 but will be ok on 40 meters. Better be thinking of at least 100 watts out if you want to be heard under most conditions.

73 & Good Luck.

Terry

 T,

2 12V batts and a dyno.......  that would be the nuts.


klc

Yup, I just need to get a 24 volt alternator that will mount right where my AC pump on my 93 Saturn goes. Those dynamotors go for about 400 bucks on eBay so that means I need to find a free one!

If you are more inclined to vintage AM gear, a DX-60, an HQ-110, and a D-104 mic will set you back about the same $$ as the Retro 75 and produce a bit more power.

Another often overlooked gem for vintage AM is the Hallicrafters HT-37, it makes excellent quality AM, CW, and SSB, and can usually be found for minimal bucks.

Add an inexpensive Heath SB-200 to the HT-37 and you will have a nice solid 150 watts of carrier (~600 PEP) which will give you a good "presence" on AM.

73 Jack KZ5A

Welcome to A.M. !! Life has now begun for you. I had the awakening many years ago and have never looked back. ;D This board is a good place to look. You may find a Ranger or perhaps a modified TS-440 that will fit the bill. If you are technical...take a look at classeradio.com. I do believe Steve has a complete class-H transmitter on a board. It all depends on what you are capable. If your not a builder the other option is a used Flex-1000 or if you have money the new Flex-5000 is an out of the box ready to go AM rig that sound fantastic.

Look for you on the bands....Good Luck! ;)

Brent W1IA

Most older ssb radios are not hard to modify for decent AM transmit. Receive can be facilitated with a Softrock married to the I.F.

Many ways to skin a cat.

Gary,

I think Jack made a good suggestion about the HT-37. It is easy to find and with 30 minutes of mods you can have it sounding hi-fi.  Chris/W2JBL has the mods which involve bypassing the ssb filter and going directly into the balanced modulator.  Also axe W1MPY/Bill.  Then pick up a linear amp and you will sound as good and loud as any of the big guns on the band.   The HT-37 with mods is possibly one the most under-rated AM rigs on the band. You can find them at flea markets or even on eBay for $100-$150 depending on condix.  Heck, I've been thinking of getting one just to play around.

The other good approach, as Brentina suggested, is to build up a class E, H-modulator rig.  That is probably the best bang for the dollar and will put you into the high power bracket.

The Retro is a nice little QRP rig, but if you make it your first rig, you may get frustrated quickly due to the inability to be heard well when conditions get marginal. A QRP rig can easily be added later, after you have a higher power station running and get an official AM badge from the Tron -  ;D

T

Just about ANY SSB rig can make a good sounding AM xmitter.  I've converted a Heathkit HW-12 75 meter monobander, a HX-10 mobile SSB xmitter, and a SOB-400 xmitter.

Trick is you feed audio right to the balanced modulator (usually a cathode follower), and bypass the sideband filter.  You need to bypass BOTH ends of the filter, or it'll still sound like hell.  Slab KB3AHE did that with his Junkston Invader 2000.

In the case of the HW-12, removing the xtal filter rendered the receiver useless as it received the whole 75 meter band simultaneously without the filter.  It was good for about 30 watts or so carrier output, as was the SB-400.  The audio response in all of them was truly amazing, and they'll do any modulation level you want, but you had to ride herd on the carrier balance control or the carrier level would creep.

A great starter rig though is the Johnson Viking II.  Any old VFO will work with it, and they're true workhorses.  That was my first AM xmitter.

Viking II is a good rig to work on.

I would look here in the for sale part.   Another good place is qth.com classifieds.    Look under HF Antique section.   Most sellers are hams and many prices are reasonable.   My personal opinion is to stay away from ebay, if a non-ham is selling and the seller claims ignorance of the product he is selling.   Local ham radio club newsletters sometimes have some vintage gear for sale.     Hamfests are another good source.

 Hard now days to find a DX 40, HQ 100 and a vfo for $109 each let alone all together ...the cost of a Retro 75 kit and case w/xtal control. $69 for just the TX/RX board kit. But whilst the Retro is probably a better receiver (where it is made to operate) than most entry level boatanhors it is still more a novelty . OK as a second or third operating position but not a desireable primary station. The HT-37 makes a decent low power transmitter as do many others. "Hi-Fi" audio is on option but not a mandate. You can also do quite well on 75 Meters with 25 to 50 watt carriers .That makes transmitters like the fine little Elmacs a consideration. Unlike most of the old novice oriented, low level modulated rigs , the Elmac has a VFO . The HT-37 has similar power and a VFO but weighs in at about three to four times the mass and a much larger package.
  The old Globe Scout series had nice audio, are reasonably priced but do require XTALs or an outboard VFO. Moving up the power scale a bit into the 100 watt class there is the DX-100 and Apache with built in VFO and 100 watt carrier. The similar power from a Viking 1 or 2 requires an outboard VFO or XTALs but gets you a rugged, transmitter built from high quality components. If you are lucky enough to find a good B&W 5100 you can score a great 100 watt rig !

   Just about any Hammarlund receiver from the post war era is a lot of RX for the current market price. There are plenty of competent receivers from the other major makers as well.
As mentioned ,there are plenty of rice boxer type rigs that do fine on AM. Get something and use it !

BTW, When buying from QTH always check the current ebay price range for that item ! All too often, QTH sharks are asking way above ebay prices for less desireable pieces.

uhh, what equipment are you using now?

Does the rice box you're using now include the AM mode?

You might want to consider the Multi-Elmac AF-67 and/or AF-68 transmitters. They run a single 6146 and put out about 40w of carrier, modulated by a pair of 5881's (6L6's). They are plentiful and cheap and work very well. I like them better than some of the other rigs because the power supply is outboard, and can be placed under the table or anywhere out of the way. The AF-6x series transmitters also have a very small footprint on the operating table. You can find them at various ham radio electronics flea markets, Ebay, etc.  The AF-6x series transmitters, paired up with a quality receiver, makes a vintage AM station that is hard to beat for the price. Just one more opinion  ;D.

Best regards,

Gary, K7EK

  I'm with Steve. Does your present rig do A.M.? My Icom 718 does well for 40 watts. You'll need to adjust the Mic gain down,also do not have the compressor on.Myself I run mic gain at "6" using Heil mic and w2ihy EQ. Sounds great and I'm on the air. Tubes rigs are great but not having one should be a non-issue.Get on the air om and enjoy..73, Lane kd8iic :)

If there are any hamfests in your area, check them for vintage AM equipment. The Heathkit DX-100 and Johnson Viking series are excellent on AM and they run sufficient power for 75 and 160 meters. Some of the newer multimode rigs also sound quite good on AM, particularly the Flex Radios and the Yaesu FT-1000. If your existing rig has AM capability, set your carrier to no more than 25 watts, then "talk up" your audio until you start to see ALC action. Then back off the audio gain a bit to keep from driving the rig into ALC. A lot of guys run such rigs into amplifiers, but make sure your amplifier can tolerate the 100% duty cycle of AM.

If you are really into AM and want to "go big", you can often obtain an old tube-type broadcast transmitter for a song. A lot of AM broadcast stations in the 250, 500, or 1,000 watt class are retiring their older tube rigs and going to the smaller, more efficient solid state transmitters. Most of those transmitters can easily be converted to 160 meters if they were originally near the top of the broadcast band. Generally, AM broadcast transmitters rated below 5,000 watts run on 230 volt single phase power. You will also hear them on 75 and a few guys have even put them on 40, although not all of them can be converted to 40 meters without some extensive work. A retired broadcast transmitter got me back on AM in 1997, after a hiatus of some 25 years.

I read your qrz.com page.  So, you are a cw op.   Good deal.  Looks like you enjoy doing some building.  You will enjoy AM for you'll quickly have more stuff to restore, fix, and build than you have time for.   ;D

If you do have a rig with an AM option (I think your qrz.com page made mention of some kind of Elecraft box) you can go the AM exciter driving an amp route, but from my experience, you will eventually find that both boring and tedious.  Before you invest a lot in that scheme, you might be better off changing course and going in the direction of some kind of real AM rig, i.e. one designed with AM principally in mind like either a solid state class E tx, or one of the aforementioned tube plate modulated rigs.  Another good one is the Heathkit DX100. 

You can find all of these rigs at hamfests, here on this site occasionally, eBay, qth.com ( http://swap.qth.com/c_radioanq.php ) even eHam.net, Ted KC3OL's midwest AM forum (google it) and the classifieds in Electric Radio magazine (do yourself a favor and subscribe www.ermag.com).

You can use your transceiver as a receiver for now, if you get a dedicated AM transmitter, so there are a few minor matters to consider:  setting up a transmit receive switching relay, and a few good to have accessories.   

It is a great help to have a way to do some monitoring both off-air and visual.   Basically, you should get an oscilloscope if you don't already have one, so you can see your transmit carrier and modulation envelope.  so, keep an eye out for an old oscilloscope.   they are no longer an expensive exotic item--you can get a good one for under $100.   Another thing that's nice to have is some kind of receiver you can activate while transmitting, even a cheap portable sw broadcast receiver with a telescoping whip antenna, to hear your signal off the air.  this is useful for telling if your audio is distorted etc. and it is also a handy thing to have for tracking down noise sources. 

The old rigs usually require some kind of high impedance microphone.   That's another thing to look for at a hamfest.

The good news for you is that you are in New England, one of the AM hotbeds in the U.S.   I bet you can find everything I mentioned and AMers to help you at the hamfests in your neck of the woods.

Rob   

Hey, we are not hard of hearing (at least most of us aren't) :D but then
most of us here are not old time CW operators  using a CW MILL to copy
30+ WPM code...

What I'm trying to say is make use of the "Caps Lock" key above the left
"Shift" key on your keyboard.  Makes it easier on the ears ;D and blends with
the rest of the conversation...

Oh and by the way, glad you have seen the light...  When you do get AM
activated, come on down to 3733 and say HOLA....

 

KG8LB's Viking 1 would be a great starter rig if shipping isn't a killer.  It is simple and reliable.  The Elmac rigs are a little more complex and not quite as easy to repair given the compact (mobile oriented) size but are easy to ship and sound very good.  Unlike the Viking 1, it has a built in VFO but does require an external power supply.

You should be able to find something at a hamfest this summer.

The questions usually go to the For sale or Trade area. There is a reason for it. Or a PM. I am not a moderator but experience has taught me to use the appropriate forum.

Elmacs have mod transformer problems, be sure its good if buying one.

If youre looking for Plug n Play and not do any work a Viking I or II is going to run $200-400 for one completely gone thru and then you still need a VFO which runs $50-100 or so. OTOH a DX-100 can be had for $150-200 ready to run.

I would not bother with anything under 100W unless you have an exceptional antenna; it can get very frustrating when you are ignored or get the "Sorry but I just cant pull you thru" report. OTOH, 20-25W into a linear will make plenty of noise.

I have several 20-30W out vintage rigs and a few SS riceboxes plus a decent antenna but I dont even bother trying them barefoot except maybe on 10-15M; otherwise they feed one of the linears here.

Carl

 

  Sorry but no shipping. It is all pick up only. If I have to move anything it will be out to the curb on trash day  ;D  

Regarding the Elmacs, the driver transformers seem to give more trouble than the modulation output tranny. I have seen plenty of crapped out interstage xfmrs but so far not a single bad mod xfmr . Some folks lay the cause for open drivers on the outgassing from the bias battery. That could well be. I have repaired a few of the transformers by opening them up and finding a connection failure right at the terminal tag strip. A little bit of careful surgery often leads to a salvaged driver. The battery can be replaced by a zener modification but timely battery replacements may save the outgassing.
They (interstage) are quite easily, cheaply replaced. For that matter the deed has often been accomplished. Transformers are an issue with a lot of the older gear but not a deal breaker.
  Power levels of 25 to 50 watts are often used by people in this locale with excellent results so don't be too shy regarding a good 50 watt rig.   We work many east coast and midwest stations regularly with 17 watts out of an old Ameco TX86 . We get fine reports from the little half wave coax fed dipole .We don't own an amplifier any longer, the Gates and the Johnson 500 along with other legal limit TXs are long as well and not missed in the least .
 Sure, higher power may be nice at times but not mandatory by a long shot. Indeed some folks need to learn when to cut back a bit on power !
  The main thing is to get on the air and find out just what you want to get done. Use any decent starter type station , you can then build from there. Making contacts on air often will take you to people that can help you find just the right stuff to populate your shack.

You can get interstage transformer replacements by Hammond at Antique Electronics Supply, www.tubesandmore.com.

Welcome to those who have also been bitten by the A.M. bug. It's a fun affliction. Remember that the antenna is 50% of your station. You can have the best equipment available but you won't be heard on a poor antenna installation. This is especially true on 160/80 Meters. It doesn't have to be expensive, but get it up as high as you can above ground. It's Hamfest season. Go to as many Hamfests as you can and don't spend your time looking at all the shiny new gear. Look instead, in the tailgate area for bargains on tubed AM gear. I prefer gear made from '48 to '62. Also grab a D-104 . You can be a pretty big dog with an HQ-140, DX-100, and a good dipole @ 65' high in the center.This is just an example. Many other rigs will do as well.Good Luck and have fun! Also, meet as many AM'ers as you can and don't be afraid to ask questions.

<<Power levels of 25 to 50 watts are often used by people in this locale with excellent results so don't be too shy regarding a good 50 watt rig.>>

I'd shoot for more than 50 watts.   That might be okay with a center fed dipole at 50 feet or more and in the daytime for 100 or 150 mile qsos, but it isn't a power level where you can be reasonably sure of getting something going under a range of times and condtions.   For a ham far from centers of AM activity 50 watts is a no-starter.   It might be okay in the daytime in Connecticut though.   But you don't want to operate a power level where you are limited very much do you?   There are times when the band is open (the low bands I mean) but there is stuff going on like rapid QSB with sigs zinging 30 dB or more up and down.  If you have some suds you don't completely fade out.  With 50 w. you won't have what I call a QSO.   At night some slopbucketeer will move in on you.  Then you have to consider the fact that not everyone operating is out in the sticks with a S1 noise level.   guys like me in town surrounded by buzzies and hash won't hear you at night. 

I'd at least go for a 100 w. rig but if you want to have a lot of solid buzzardly armchair copy QSOs be thinking about QRO, unless you are one of 5 hams in the country who can put a dipole up around 150 feet.   For most of us we have to settle for a combination of power, compromise antenna height and audio punch and get by with that, with antenna height the real tough hurdle.

  Had many real good QSOs at 25 to 50 watts , Night time , Day time and prime time. You can start out with low power and make low power mistakes early on. No need to bust the bank early on .

  We have had just about every power here from the 2 watter Retro up to legal limit rigs. Many real fine, real QSOs at decent distances with 25 to 50 watt transmitters .   In fact at least 60% of my AM activity is at the 50 watt level on 75 meters. It is often surprising to some just how little difference there is between a 50 watt TX and a 100 watt tx from the same station.  


  Again, the power is nice at times but not at all a pre-requisite to having a lot of fun and many fine, real QSOs on 75 AM. Don't rule out a 25 or especially a 50 watt tx as a first AM station. You can always get a bigger tx later on, but you may find you want to hang on to the 50 watt rig as well . I did .

 Whatever you wind up getting should work out just fine.  To bad you don't live a bit closer. I could send you home with a good old WRL HG  303 modulated by a Stromberg Carlson PA amplifier . An unusual set up that works fine. A pair of 7027s modulating a single 6146. Or, maybe a Viking 1.

    

+1 for the Viking 1.  I own one and have been happy with it.  A good starting point for AM.

Yep, the last thing a new guy wants is to be ignored because he is in the summer QRN, the birdies from home electronics, or splattered by evil slopbucketeers.

I got that 150' dipole beat by 20' which has a nice NVIS lobe as well as a low one with plenty of ground gain due to the hilltop. That helps when in a roundtable with stations covering a few time zones. A sloper starting at 90' fills in some holes but even so there are many times a 20-50W rig just doesnt cut it on either antenna so I almost always run a linear with those rigs rather than have others be frustrated and me being aggravated 8). It doesnt sound like much but 9-12dB can sure make life easy. Even going from 25 to 100W is 6dB; even a 4 square or a 2 el loop doesnt offer that much.

Carl

Yep.
  Heck some guys use a KW to talk across town,and use it always. Some others do quite well with 50W at very  good distances. What one needs another does quite well without.

  
 There are plenty of folks having a lot of fun with 50watt rigs . Still others are miserable with twice the legal limit .