The AM Forum

Hello all,
I just got my Johnson Valiant working but I don't have a receiver yet.
What would be a good receiver for AM without breaking the bank.
Thanks,
Don W9BHI

SP-600

I have the A-2 and A-3 with the fake filter network instead of a real mech filter.
I like the A-2 the best though.
The NC-300 or 303 is good too.
If you have some more modern stuff the 75S-3B is good but the others have a bit better audio.
I got a SX-101mklll and it's pretty good....cool looking too but ya need a strong table.
HRO 50T1 but is a pia with the plugin coils but sounds great.
Early HRO's with black wrinkle paint....it goes on and on but these are popular and not much $$.

Or a better question might be, what receiver can't I use for AM :)

There are a lot of criteria, for example maybe you want to age match the Valiant i.e. HRO-60, SX-100

or choose one that will also do a fine job on vintage SSB i.e. SX-101, 75A-4

Many more modern receivers do a fine job, I sometimes use a Drake R-8 with my Ranger/Desk KW instead of the SX-88 and I have both a Pierson KP-81 and a JRC NRD-515 paired with my Viking 500.

Almost any decent communications receiver will do OK for most AM use.  I would stay away from the lower cost units (i.e. NC-60, S-40) since selectivity and calibration are both going to be marginal.

If you can find a good local deal on a decent receiver start with that and then decide what is most important to you in a receiver.  For me, I will take performance under interference conditions as the most important criteria but others are much more biased towards fidelity.  Spend some time with a receiver you like and then figure out what you want in a receiver you will love. 

Check into the Midwest Classic Radio net on Saturday morning AM on 3885 (7:30 local time) and you will likely find something available in the greater Chicago area-it is also a good way to get in touch with some of the local AM aficionados and perhaps get some hands on experience with different receivers.   I am net control on November 12.

http://amfone.net/ECSound/JNRECS.html

I have the Collins R-390A on my wish list. It's Numero Uno on the above list of receivers.

 Hi Mike ; Love my 390-A. Got her last February from Rick Mish aka Miltronix in Toledo. You deserve the best..Break that piggy bank..Glad I did..The performance is there and limited only by the quality of the antenna you plug into that Twinaxial input.Personally, my second choice is R-75 Icomic.
 73 laner

Try an SX-28 to find the signals and listen to them. It is not as precise or sensitive but it sounds better, has almost as many controls, and uses Octal tubes. Save the 390 for when things get tougher.

Depends on what is meant by "not breaking the bank".

SP-600  R-390 SX-28 's are not exactly CHEAP.. expect to pay several hundred.  They are excellent radios.  I have a National NC-300 which can usually be found a bit cheaper than the aforementioned receivers and works very well for my purposes.

To me, An NC300 matches a valiant nicely. So does the HRO 50 or HRO 60. 

SX28A is my favorite for AM use,. however, They will need a complete redo. Otherwise, The performance is so so.

SP600s are great, However, The audio is complete crap.  You will want to run external audio and a decent speaker. 

R390s are R390As are complex and break down alot.  I own Several of both. Guys that know how to fix them, Love them.  If you get a good one, You are will love it.  If you get a bad one, Look out.

C

I vote for the pre-war Hammy Super-Pro's.

Heap big PP triode sound.

73DG

it would help if you gave a precise upper spending limit.

some things to read:

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

http://amfone.net/ECSound/JNRECS.html

found this helpful too--not much numerical data out there on vintage performance...

http://www.w1vd.com/BAreceivertest.html

The guides are helpful in that they tell you receivers to avoid. 

don't worry too much about a rx's rep for poor audio.  That's pretty easy to get around if the problem is a weak single ended audio section.

Rob

"To me, An NC300 matches a valiant nicely."

.

Hi Don,

What does "breaking the bank" mean to you?  And, what type of performance are you looking for?

Someone mentioned the SP-600, and those are pretty good.... a simple mod to the AGC and it will perform quite well on AM.  If you want to be able to receive SSB with a product detector, you either have to build one into an old receiver, or you're into another realm.  Unfortunately, most modern receivers I've worked with have an AGC problem where the modulation causes more AGC voltage to be developed, resulting in an annoying "compression" effect.  The AGC is also generally too fast.

A BC-1004 (or BC-779 - same family) (there is also a civilian version) would work very nicely, and they aren't too expensive.  Typical old military AM/CW receiver - no product detector, but there is a BFO.  Remove the audio tubes and pick the audio off the audio gain pot; run it into an external hi-fi amp and speaker.  Nice sound!

Anyway, could go on and on..

The Flex is the ultimate, but (at least for me) that would definitely break the bank  ;)

My favorite is the Hammarlund HQ-140X or XA.   Very reasonable prices, better for AM than some of the newer Hammarlunds.

One of the criteria I think is the most important for AM operation is the audio . Just like a transmitter ,a receiver should have nice audio. I have a SP-600, and  a r-390a which are great receivers but as far as I am concerned poor audio,although I like the filters on the SP600.

  My receiver of choice is a RCA AR-88,or CR-88 which was the dual diversity model . The AR-88LF from 1939 is my favorite receiver. Though I have to say it the CR-88 has even better audio.It is a treat to listen to every time .I rarely hear much mentioned of this receiver on here.

 Also it is an easy receiver to tune around on. 6 bands and if the gears are in good shape a good spin of the knob and you are completely across the dial. As well it is one of the best designed receivers of the era. Easy as pie to work on.No fancy turret assemblies or gear operated rf racks. Great selectivity and on the CR-88 crystal filter.

  If I remember right this was also a favorite receiver of Sam W6HDU . He wrote a article in the April 1990 on them . Ozona Bob had a couple of them and turned me onto them.

The only draw back is they are getting to be rare as hens teeth , especially in the states,seeing as they were mostly used in countries other than the US.

The  best for audio was the 6V6 push pull SX-28 hallicrafters ,but they do require a lot of work generally after you get them and the parts Bill Halligen  used were bargain basement so expect to replace every resistor and capacitor and prepare to curse those wafer switches from hell. But when you get them all tuned up proper and turn on that BASS switch YEEEHAH !

As above, the NC-183 has two 6V6 in push-pull, and you also have to replace many caps and resistors that have changed in value.

I'm not arguing with that, but it seems to me that one of most important criteria is variable bandwidth. Good audio is fine, but if we can't hear the other station, it is a secondary consideration. When we are in the midst of QRM, we can narrow the passband so that we can copy the other station comfortably; but if the band is clear, then we can open it up wide and enjoy better audio.

My Hammarlund BC-779 had continuously variable bandwidth, and I miss it.

Possibly one of the best values for a high quality receiver great on AM is the National NC-183.

Greg

The BC-779/BC-1004/SP-100/SP-200/SP-400 has it all - variable bandwidth AND superb audio.

Some you might not want are the Phasing type rigs like the SX100 or SX101.  There are others.  They are limited down in bandwidth and for decent fidelity you need a spot on perfect alignment. I own both.  When I use them, I miss the SX28 or SX42s audio.  

To me, One really important feature is the antenna loading Adjustment.  Most hallicrafters rig had this. The SX42 does not.  As a result, Its not a perfect match to the 50 ohm input on the tuner and the performance suffers. On the 28, you can just peak the Antenna matching knob and get peak performance on any band to the antenna you are using.  I am thinking of adding this to the SX42.

One of my old favorites is an SX110.  Cant get any simpler, here.. Single conversion, Super het reciever. It has Xtal filter and it has fantastic audio.  The audio from this old radio is way up there with the best of them in my opinion. Its great for good band conditions and hifi am.  Its not good for a ground band, A real weak signal work or a band that is crowded with SSBers.  These go for $60 to $100.  The SX110 has the Antenna matching knob.


 


C

If a receiver has any decent sensitivity at all, precise matching to the antenna won't be an issue.  Most commercially made receivers have more than adequate front-end gain. In fact, many have too much RF gain. I have to use a 20 dB attenuator pad with my 75A-4 with certain antennas to avoid front-end overload. The loss due to antenna impedance mismatch with most receivers will hardly be noticeable.  That said, matching the antenna to the receiver with a resonant tuner will result in a few dBs improvement in image rejection if that is a problem, as it is with many "vintage" receivers. The only band where I even bother to check the antenna trimmer adjustment is 10m.  It does make a difference there.

Although not what I consider a "vintage" receiver (although some may disagree), my all solid state Kenwood R-1000 does a good job on AM, although I use it mostly as a SWL receiver and test instrument. The audio is almost as good (using the built-in envelope detector) as what I get with the 75A4/Sherwood sync detector combination, and sounds very good through a small bookshelf type stereo speaker.  It has a nice 3, 6 and 12 kc/s filter selection. I think it would make a good ham AM receiver, but I would recommend a tuned circuit between the antenna and receiver, since the front end runs wide open through a series of band pass filters. Downsides are that a few birdies exist over the HF range, and I wish the i.f. bandpass filters were selectable independently of mode (AM/CW/SSB).

I picked up an NC300.  I like it.

I guess it's my time to chime in. This is another topic that has been discussed ad nauseum here. There is no right answer, PERIOD! /short sweet, and simple.
It's kinda like saying: How do you make a cup of coffee? there is no wrong answer. You make it the way that YOU like it and that is the right way. At least for you. Everybody's opinion and preferences are different.

If one is looking for a good receiver, there is no "holy grail". Everything requires some kind of a trade-off. The absolute best thing to do is to set one's arse down in front of as many different receivers as one can, under as many differing operating conditions as possible and formulate your own opinion. Every receiver out there has a different personality, sometimes even 2 of the same make and model will will behave differently. That is why I have 15 of them.

You may find that the ones you like the best are the ones nobody else likes, or vice-versa. The only way to find out is to road test as many as you can before making a decision. Simply asking "which is better" on a BBS like this one, usually envokes the good old "Ford vs Chevy" scenario all over again.....................

Yup I agree - SuperPro for room filling YEA-AM. Lots of room to work underneath. You have to love triode connected 6F6's in class A Push Pull. All sorts of these receivers are around for low dollars. The SP-200, 400 and the military variants. They do take a pretty beefy external power supply - sort of like you would have on a novice special 6L6 transmitter but not a big deal if you have an old TV transformer as a starting point.

A lot of good suggestions have been thrown out here so you have a lot to consider.

A parallel question might be, what is the best vehicle :)  Most of the time I run around in my Cadillac CTS that gets decent fuel economy and is quick and agile but it doesn't go to hamfests with me because the kind of stuff I bring home fits better in my full size Sierra 2500HD diesel pickup.  Choice of vehicle and choice of receiver is similar-it depends upon the situation at a given time.  I own a lot of receivers from very early regens through later model Watkins Johnson and Racal and none are what I consider best over all situations.

For very tough conditions I like the HQ-170A and Drake R-7 although the Hallicrafters SX-96 and its 50.5 KC final IF selectable sideband relatives do a fine job.   For nice audio I like the earlier Super Pro models with variable bandwidth.  They do a nice job over a wide range of conditions but are not as selective as the HQ-170 etc.  My Pierson KP-81 also has nice audio and with a wide range of high and low pass audio filters plus crystal filter it does OK under reasonable conditions.  For the most fun, I like the art deco look of my Breting 14AX or using my very vintage Hammarlund Comet Pro.  Switch to CW and the 1930s Navy RAL regen is a winner.

If you have room, perhaps choose two receivers as a start since one can never have too many :)  I would look for one that can pull weaker stations out during tough conditions and you will face that scenario fairly often here in the Midwest.  This requires good selectivity and selectable sideband on AM is worth its weight in gold since you can virtually make interference from above or below disappear.  For a second receiver, look for something with style along with wider bandwidth and great audio.  If it turns out you don't like it you can probably trade it to another ham for something you like better.

It would be interesting if some people who knew their receivers would put their heads together and compile another list of AM receivers, like the one at http://www.sherweng.com/table.html (the titles of many of the columns would be different, yes.)

Some columns would be audio quality, shape factor (selectivity), whether or not it had continuously variable selectivity, intercept point, ???? (fill in the rest. :-)

Board member Jay, W1VD has done a lot of work in this area.  See this page http://www.w1vd.com/BAreceivertest.html

The SX-100 and SX-101 are filter receivers, not phasing.  The filters are cascaded 50.5KC LC networks, with switch-selectable coupling for the selectivity positions.


The antenna trim control isn't an antenna matching adjustment, per se; it trims the capacitance in parallel with the first RF input transformer to compensate for tracking error.  This can be caused by any number of things, antenna reactance being just one.


The SX-110 is basically the same circuit as the SX-99 and many other Hallicrafters radios.  It shares lineage with the S-20.


 

For contemporary matching to a Valiant the 75A3, HQ-140/150, NC-183D, NC-300, HR0-60 are within that range of years.

Other earlier ones would be:

Pre SP-600 Super Pros if you have room for that overkill PS used with the military versions. A BIG negative is no calibrated BS but digital readouts are available plus oscillator stabilizers. All Hammarlunds drift.

NC-173, NC-183, NC-200, NC-240D, HRO-50, HRO-50-1. The 173 is often overlooked since it was just a mid priced radio but it runs circles around a HQ-129X for sensitivity on the higher bands. The others mentioned all have PP 6V6 audio and are all priced reasonable. The HRO-50-1 has 3 IF stages with 4 tuned circuits per stage so the skirts are pretty steep.

HQ-120X, HQ-129X. Older versions of the 140, etc but just fine thru 20M without mods. All HQ's from 120 to 150 have 3 IF stages for fairly good base selectivity.

GPR-90 if you can find one and afford it.

My notes show the NC-183D, NC-300, SX-28, SX-101/101A, HQ-129X/140X or XA leading the pack in actual QSO's Ive had.

Carl

FWIW,

I am content with using either a vintage HQ180A, which matches the Valiant's size, or a Kenwood R5000, about 8 of which would match the size of the Valiant.  Both work well for what they are.  I also use a K3 for its synchronous AM receive ability.   (Plus the K3 sounds great on AM driving an amp.)  The 13, 6 and 2.7 kHz filters in the K3 allow for a lot of flexibility.  Just my $0.02.

I use external audio processing with the Valiant, but the internal processing on the K3 sounds really quite good on AM.

73
Ted  W8IXY

Use a HQ-110A with my Viking II.  Not bad for AM if you let it warm up enough.  Have an S-85, but selectivity is bad; same for the S-77.  75S-1 is OK.  None of these have the audio quality of the older PP 6L6 audio output rigs. Have not found one of those I could afford yet.  Homebrew receiver is great for AM, but need to add a better audio section than the original one I put together to get it running.  The 30's through mid 50's rigs are probably the best as far as audio goes, it's just dependent on what you want to pay for good RF sections ahead of it.

True but most are not ones he did the restoration work on and got to peak performance. Nor does it cover any that have had well known performance mods.

What are the well known performance mods for a Mackay 3010B?

I would like to test the performance of some of my old Receivers.  How do I get started?   


Time to open the handbook again.

Ask JN, this is a ham forum ;D

A couple of HP 8640Bs, a bunch of step attenuators, a good VTVM, an audio distortion meter, a S/N or SINAD meter, and a good scope.

A HP service monitor would do most of it, but the phase noise of the sig gen is fairly high in comparison to the 8640B.  To do it right you need extremely low phase noise RF sources.

Test procedures are in any later ARRL handbook.

Great. I actualy own most of that gear including three Step attns. I also have a Motorola service monitor.  Just need to read up on how to test. I do not have a distortion meter. I used to have one but its been missing for years.

Carl, I dont understand your comment.

C

Don't try to use the sig gen in that Motorola for measuring dynamic range, blocking, or S/N - it's crap.  Use 8640Bs or one 8640B and a homebrew xtal oscillator.

Which would be a moot point as that would disqualify the receiver based on known performance. Instead, it becomes that receiver in name and visual appearance only. Buying one based on this or doing the mods after using it for a while would make more sense.

A couple of major factors come into play in deciding: HiFi audio and on-air, battle mode performance. Between Johnny's receiver list and Jay's performance testing, you can get a very good idea of where to look. There are a number of great receivers out there, but IMO no one receiver handles it all well.

I'll throw in with what several have already said: the pre-war Hammarlund Super Pros (SP-10, 100, 200, and the postwar 400, not the 600) are as good as it gets audio-wise, with their push-pull 6F6s and variable bandwidth out to 16 kc. In top trim the crystal filter helps quite well with interference. But for hand-to-hand combat conditions, it's tough to beat the combination of mechanical filters and passband tuning offered by the 75A-4. The audio can be improved somewhat with a wider filter and a few other changes, but it will never come close to sounding as nice as a Super Pro. The R-390A is probably the best weak signal receiver out there but a PITA to tune around much with, and weak signal AM isn't a lot of fun for me. 

As Slab indicates, trying to do it all with one receiver will involve trade offs. All the more reason to have a few on hand to choose from.

I was replying to Steve

Don't worry, most people don't understand my comments too.

I'll leave the finer points of getting the exotics to play well to you and Johnny. My experience there is nil.