The AM Forum

So I have been looking for another project to start on.  Been listening to 10 meters and hearing quite a bit of activity in this area on AM. While doing a bit of shop cleaning I ran across an old radio I used to love talking on 20 years ago.  Remembering back in the day how great the AM audio was on this radio I got to thinking. This should be an easy conversion to 10 meters.  The radio I am talking about is the Tram D201 23 channel cb radio.  It is an all tube rig, uses a 6L6GC in the audio circuit, and has a VFO.

I am going to go through this old radio and give her a try on 10 meters.  Already did a little surgery and got it up on 28.350 without much trouble. I have not talked on a cb radio in over 20 years but I do collect a lot of them. And have some that I bout 40 plus years ago.

Going to give this a shot and may even do some YouTube vids on it.

That was a dream radio back in the day, along with the high end cobra console later on.
When I got into radio in the 60's CB was a normal radio service, no trash talk.
All the good radios were tube radios.

Agree with all of that.  I have a few other vintage ones. Browning Mark 3, Sonar 23, Johnson 223.
I think the Tram would be the best for this modification.  VFO is more stable than the Brownings were.

That's why many of us went with the Siltronix VFOs on the Brownings. The Mark 3 had a really hot receiver and with the Siltronix slider it was a great 11/10meter receiver.

Search the CB sites on the web for tons of info on converting the Tram into the "upper channels"!

Yep. The mark 3 I have was given to me after a freind passed away 13 years ago. He ran a cb shop for 30 years and I worked there part time. This particular radio was kept on a top shelf in the front room. There was a gas heater on the wall and the heat was insane in the cieling. Every crystal in the transmitter was bad but one. Perhaps the heat help age them further. Any way I put a Siltronix VFO on it and it has sat on a shelf in my store room ever since.

A guy names Ray Phelps in Elkin NC has a conversion he does to these radios so the receiver and transmitter tracks off the VFO and does away with the crystal side. I called and inquired about it but he will not give the information away. He gladly do it for the sum of 150 bucks  :o

I dabbled in cb back in the day and still have tons of mods,books, tubes and parts. Just hate seeing these sit there and do nothing. Thought about converting one to 40 meters one day. But that is for another topic.

I have Sams cb photofacts 1-25 available for sale .... these cover the early ones ....want to sell as a group

moderators please let sit here for a couple of days before moving ...thanks

I've always had three radios that I'd like to put on 10 AM - Browning Eagle, Demco Satellite, or an original Tram Titan.
Yes, in the day they were status symbols!

My first real radio over 100mw was a Lafayette mobil rig, solid state, no meters or knobs other then the usual three, but friends had a Kriss tube job with meters and all kinds of knobs, tunable receive, mic gain and everything. Way over my lawn mowing for $3.50 each job budget.

There was a cobra that had more knobs then the Gemini spacecraft I think.

A few of the early 23 channel Lafayette radios were made by Hammarlund. I'm in the process of restoring my "roots" radio, and HB-444-25A. That where my radio addiction all started in the 60's! Still got my original '67 Lafayette catalog in the "john" as reading material!

I've done this.   Kept the 6l6gc in the final,  changed the audio output to a KT88 in  23 channel version,  and in 40 you must use an earlier tube  (I'll have to check,  but  envelope was smaller.   The longer channel selector board made the smaller envelope tube a necessity).

Once all was said and done,  I got very good audio response,  more positive peaks than I knew what to do with,  and a good running radio.

12 watts carrier is about to max.  50 to 55 peak was normal.

The negative bias supply is nothing more than a voltage drop across a resistor.   Much better linearity by adding a lv bias xformer,  especially if you hotrod the audio section.

The mod xformer is decent.

I have a source for NEW audio boards if you end up needing one.   VERY common fault of the tram Cb sets.

I've done a few.   Feel free to ask any questions.

--Shane
KD6VXI

A slow moving fan is a necessity,  as is recapping the entire radio.

--Shane
KD6VXI

w4bsf,
I will let a few folks know about those.


Good information guys, brings back lots of memories.
These were real radios back then.

I did not know about the Lafayette radios.

Shane,
Thanks, I am sure I will have some questions as I move along with this.
I also used to make the boards. But since lost part supplier for the connectors. I have seen these burnt so bad components just fall right off.

Before I got out of repairing cb radios I made it mandatory that all capacitors were replaced or they would take it else where. Kust too much of a nightmare chasing ghost from bad caps.


Had this little gem in the shop last week. man I have not seen one in this shape in ages.

Only one Lafayette model (HB-266) was made by Hammarlund. On the Hammarlund side, it was known as the CB-23.

(http://www.cbtricks.com/radios/lafayette/hb_266/graphics/lafayette_hb_266.jpg)


(http://www.retrocom.com/images/hammarlund_CB23b.jpg)


Although the HB-444 series were nice looking rigs (I had three at one point), they all had trouble handling strong signals.

Front end overload?
And could it be corrected?

I'm sure you could make improvements to the front end, mixer, IF chain, and the AGC circuitry, but it wasn't worth the trouble or energy. Even new out of the box, we sold quite a few of them during their life cycle, strong signals, especially in metro areas, would bugger them up. If you were out in the boondocks, generally they would be fine unless there was a strong "E" opening. I sold the last batch of new old stock meters to some guy down in NC several years ago. The front panel of the meter had the habit of crystallizing making viewing difficult and/or annoying.

Ah,
Sounds almost like it was receiving a lot of intermod where different frequencies in the city would mix with the IF. I could be wrong though.

If I recall Frank at Tar heel radio over in Chocowinity sold a few of those many years ago. He is one of the oldest cb radio repair shops I know of in NC. And at 74 years old he is still in business. One of the best Tram repair techs I ever met. I drove down last Friday to see him and picked up a oscilloscope in need of repair. A 35 MHz Dick Smith which is the same as the JDR 3500. High voltage supply failed. Remind me to tell you how much I hate HV switching supplies. I would take heavy iron and a doubling circuit any day.

Anyway I think it is going to be fun bring new life to some of these old rigs. Should make for a good winter project.

I've had a few Trams here in the past, along with a lot of other CB base-type rigs I acquired through the years.  Most found cheap at yard sales or sitting by the curb waiting for trash pickup. Fix and clean them up and flip them back at the next hamfest. Never desired to even start a collection which would just amount to more dust catchers and used up shelf space. I have one CB in the work bench area which I use as a signal source and monitor.

I have had a project on and off the bench for some time now. It started life as a Siltronics
VFO and a HW12. Really only part i saved was the HW12 case then  married the VFO into that case and cabinet. Still working on it and populating the boards.  The reason i started this was to do something
with a bunch of CB's i was given by a now silent key ham buddy.  The rig will start as a 80 meter
AM receiver. I can add to it later on.
(http://i1372.photobucket.com/albums/ag347/Papawlear/CBVFO80M_zpsfusxuf7h.jpg) (http://s1372.photobucket.com/user/Papawlear/media/CBVFO80M_zpsfusxuf7h.jpg.html)
(http://i1372.photobucket.com/albums/ag347/Papawlear/CBVFO80M2_zpsmdqcw6gp.jpg) (http://s1372.photobucket.com/user/Papawlear/media/CBVFO80M2_zpsmdqcw6gp.jpg.html)

Now that is an interesting project. Please keep updates as you move along on this.

Worked a lot of overtime this past week. Not much time in the shop.
I did get the D201 on the bench and decided to give it a good once over. Replace caps and tired out components. Lots of solder reflow and inspect tube sockets. This one is not the hand wired chassis.

Someone in the past has partially rebuilt the BA board. But they used ceramic resistors which I think is a no no in this circuit. Carbon or metal film would had been a better choice. At least the board is not burnt up like some I have seen in the past.


(http://gokarters.com/smf/index.php?action=dlattach;topic=2492.0;attach=2020;image)

I hope to get more done to this today but have a Yaesu 757 and a Kenwood 120 on the bench that has to be looked at first.

Being audio,  the added inductance of the wire wounds don't disturb the circuit appreciably.

I'd replace them,  once again,  and stand them off from the board.   Mine all look goofy,  wire wounds sitting half inch or more off the board,  but none of my boards are crispy,  either.

--Shane
KD6VXI

Agreed,
Bad enough there is a hot tube on the foil side and then hot resistors on the other. Will cook the board till it is a golden brown lol. More like chard black...
Good idea to move those resistors up off the board.

Here ya go, Buddy - TR-72C w/27C base unit. Also a Titan II w/XL-100. Corsair would actually be correct.

I grew up in northern New England and spent a lot of time over around Winnesquam, Wolfboro, Laconia, and on Winnipesaukee. Knew a few folks who worked for Browning and Tram back in the day. Hand wired, Collins mechanical filters, quality components, certainly the Rolls Royce of 11m.

Also knew a number of true old time hams (licensed in the 30s-40s) who swore by their 11 meter radios. When the FCC converted the band to the Citizens Radio Service (or whatever), these guys simply got a license and radio and used it locally. Their description was that 11 meters was the 'local intercom' before the 2 meter band came into widespread use.

Thanks Todd for sharing that story. And for posting those beautiful old rigs. They look like they are in excellent shape. Really appreciate that :)


Did not get a lot of time to work on the tram yesterday. A guy drove 70 plus miles to bring me his Kenwood 120 to look at. His crappy power supply went south and threw 24 volts into the rig. Was an easy fix.

The 757 I was working on took most of my time to troubleshoot.  Rig lost it's -8 volt circuit. Q01 (2SC496Y) went bad. Now to find a replacement.

So back to the tram. Final tube is bad. Got to check and see if I have a good replacement.  Spent a little while checking resistors and making a list of caps to replace. Used the USB microscope to have a look at some solder joints. Finding a few that needs to be reflowed. Someone has done a bias mod to the output section.  Have to remove this and get it back stock.

Ya, and the 6BM8 behind the S meter ran so hot that it melted the plastic! Just starting to look for all the caps. I also have almost a complete set of NOS tubes in Lafayette boxes.

Do you recall who he was? My meter suffers from that condition

I've talked with him several times after that (he was always looking for Lafayette parts) and all the meters replaced defective or crystallized meters. Actually he was still short one or two meters. As far as I know, I was the only person who still had a stock of those meters.

The Johnson Messenger One, II and 202 are easily moved up to 29Mhz. I have all 3 of these moved to 10 AM. I have to move the crystals from one transceiver to the other. Power output is around 7 watts.

I also have a Johnson Messenger 223 that's DDS VFO controlled on 10 AM. The DDS VFO is from N3ZI. I use a small universal single transistor amp to bring the VFO signal up to a usable level. Power output is 5 watts. The Messenger One sitting on the shelf behind the Messenger 223 is one of I moved to 10 AM.

Ten has been open a few times this past week and today, mostly to Oregon and Washington state.

73
Mike W5RKL

  yo'

   Flashback... My first "CB" was a Heath Apache
paired up with a Laughatit Comstat 19 with "tunable"
RX.. Sweet!

        It took a little screwdriver action to get the
Apache on 11m but was "do-able" even when I was 10...
I'm glad I didn't but would have traded it even up
for DX-100...

/Dan

Question,

Any of you guys remember the hallicrafters CB-3A?
Said to be able to cover 27-29 MHz.
I was just given one and will pick it up tomorrow.

It's an 8-channel basic receiver-transmitter. Requires separate receive and transmit crystals.
http://www.cbtricks.com/radios/hallicrafters/cb3a/ad/index.htm

Got that Pete, thanks.
It's in my Sams book.

Since it is "Hallicrafters" was wondering what the build quality was. Wonder if it was built by them or just a re-badged unit with their  name on it.


Looks simular to an old RCA I had.

Early models were made by them; some of the later models were made in Japan. Have no idea of build quality. No tunable, no meter, no stellar cosmetics, not a lot to excite me.

The Hallicrafters CB3 quality is very similar to the Lafayette HE-20 series. The HE-20 series were built in Japan with Lafayette's name silk screened on the front panel. The CB3 and the HE-20 both have the same 1.650Khz IF and very similar circuit. I have an HE-20C that I used when I was in high school, long time ago. The receive crystal frequency is 1.650Khz above the receive frequency so they can be moved to the transmit sockets. I did that with channel 18, 27.175Mhz which tuned the HE-20C right up on 28.825Mhz rather easily with about 3 watts into the 50 ohm dummy load.

I have the Sams CB3 pages which include the full schematic and alignment instructions plugs pictures pointing out the cap and resistors etc. Drop me an email and I can send the pdf files to you. The files are not big.

73
Mike W5RKL




The CB3 has about the same circuit layout as the HE-20 does, it has the same 1.650Khz IF

73
Mike W5RKL

Incorrect. The Lafayette HE-20, 20A, 20B, and 20C were all manufactured here in the U.S.A. The HE-20D and 20T were manufactured in Japan. See the ad: http://www.cbtricks.com/radios/lafayette/he_20c/ad/index.htm
A number of Lafayette's early amateur and CB products were manufactured here in the U.S.A. A number of CB manufacturers used the 1650 KHz IF in their products.

Thanks for that info guys. Either way I only see a bit of history in this old radio. Nothing spectacular.

Back to the D201

I stand corrected. I thought the HE-20 series was made in Japan. Thanks Pete for the correction.


Yes I'm sure there are others that have the same 1.650Mhz IF frequency. I was simply making a statement that the CB3 and HE-20 have the same IF frequency, nothing more.

73
Mike W5RKL

When I was first hired part-time by Lafayette, the HE-20 series was a hot seller. Typically I could move 5 to 8 of them on a single Saturday(our busiest day). In the made in the U.S.A. category, there also was the Lafayette CB HE-15 series, HE-90, HB-111, HB-115 series, HB-200, HB-222, HB-266(made by Hammarlund), and the HB-333(made by Polycomm). In the amateur category, there was the HE-35 series, HE-45 series/VFO, HE-50 series/VFO, and the KT-390.

Back in my junior high/high school days I had the Lafayette catalog, loved to page through it every day. I wanted an HE-20C but couldn't afford it. I got lucky a short time later and bought one from a friend for $25. Took me 6 months to pay him the $25. Back then $25 was a lot of money for me, I worked part time after school at a greasy spoon, "Red Barn". If I remember correctly I only made $35 a month. I was also paying for my Suzuki 150 I used to get to and from work. Gas was 27 cents a gallon back then. I'm sure you remember those days. I solid the HE-20C and the Suzuki 150 many years ago when I joined the Navy. I recently found an HE-20C in excellent condition along with the other HE-90 I also wanted. They sit on the shelf and I power them up every now and then to keep the "cob webs" out. I don't talk on them, just keep them for memories of those old high school days.

73
Mike W5RKL

I visited a firetower in New Hampshire as a JN: the lookout was using a Messenger, but it was on a fire service frequency. I remember being surprised when I looked at the license, but IIRC it showed 29.8xx or thereabouts.

Bill

I'm not surprised since the vacuum tube Johnson Messenger transceivers can, with the correct components, operate on any frequency from 25Mhz to 50Mhz. The proper components for each 5Mhz spread of frequencies are found in the Johnson Messenger 202 parts lists.

The Johnson Messenger One, Messenger II, and business band Messenger 202 are very easy to move up to 10 meter AM.  I have to physically swap the crystals from one radio to the other. I have all 3 of them on 10 meter AM, worked both coasts, Canada, and Italy with only 5 to 7 watts into an inverted vee. It's fun when the band's open.

73
Mike W5RKL

I forget which CB it was, but I once had one with the 1650 IF and  I just swapped the RX and TX crystals and retuned and it was on 10M.