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Post by SteveInOregon on Mar 17, 2011 12:24:31 GMT -5
As You nice folks here know I have been wasting my money on, ah ah I , I mean "investing" , Ya investing my money in to old SB - CB gear, ;D lol.
So I got a D201-A MexiTram in average to fair condition.
It is working , I am using for the last 3 days.
We checked all the tubes, most say 'Tram' right on them and we checked them with a checker and they do not leak , no shorts , they put out better than 100% so tubes are all good.
Me and my technician buddy have never had one and so we wish to probe the minds of radio genius and generosity here for some guidance.
We found a bunch of problems, such as the small vertical board ( BA board ? ) that is new or new'er was loose causing a horrible 'pop' noise with any slight vibration on the or around it, so we probed the radio with a plastic screw driver and isolated bad solder joints, we soldered that small board from the bottom and cured that problem.
1) There is a "hum" from the transformer , darned if that is not the the same musical note of hum that the commercial 480 volt transformer in the panel room next door make, lol, so we are wondering if the large aluminum looking caps next to it can be the possible reason for transformer hum as my tech suspects it is.
The TX power is fine, the lights do not flicker or dim, it just hum-mmmmm's, so in a quiet room it will drive a person nut's, lol.
2) The crystal -channel section is way off, so when I select ch 38 / 27.38.500 via the channel selector it is actually on 27.383.63 , it is so far off that it is useless to even try and use the crystal channel section.
I did notice that the crystal-channel switch is the newer black one.
3) In VF0 , the TX and RX are different , so to me they are not 'in sinc' and so I hear a good tone from my friends talking to me but I send a high off freq signal to them.
Note: I sort of neutralize the clairifier, what I do I set the califier to 12 o clock 'before' I even tune the VFO, but once I do this and after a min I have to tune the clarifier again clock wise all past 3 o clock in order to tune incoming signals.
4) The VFO in passive receive drifts up, my buddy is on a rock solid Kenwood we use as test for being 'on freq', that and I turn my Kenwood on and turn turn down the rf gain and speak to myself and I find and after letting the Tram sit and warm up for 30 min it still wants to creep / drift up in freq a bit over a 20 min time period, not much but it does. I am willing to accept this as normal old tube radio issue but wonder if this will turn into a Siltronix super drifter if I don't take care of some sort of alignments that may need to be done ?
5) the VFO reads 39 when I am actually on 38, is this mechanical mis-alignment or electrical or both ?
6) Bleed over: This Tram has some of the worst adjacent channel rejection of all my radios. Local truck drivers passing by blow out my Tram .
I am always on 38 LSB , they are always on 15 or 17 AM and I am getting killed by them.
My Stoner almost completely eliminates any bleed over, so the Stoner sets the bench mark for rejection of unwanted signals.
Is a Tram in need of something to help with nulling bleed over, should we check something ?
7) The meter is sluggish, on my other radios the meter swings with my modulation fast and furious, the Tram meter moves in s-l-o-w m-o-t-i-o-n on both TX and even in RX.
8) When You key up ( I am using a amplified D104 turned down for a clean audio) sometime, again 'some times' the meter the second You key up it swings far over to the right ( pegs in the Red ) then drops back after a split second to about S3 / 1 watt and that is the average base line were it fall back after a breath / pause in my audio.
9) There is a 'pop' when I key up coming through the speaker, this is instantaneous along with the normal relay 'click' , so i have a normal relay click and an electrical 'pop' through the speaker.
10) The speaker is original and seems to be dry and lacks fidelity, what speaker brand, dimensions and ohm should I replace it with ?
11 ) Cosmetically, does any one make stick on over-lay's for the face, because the white lower section of the face is dull smokers off white, and someone has used a harsh cleaner to take off the chain smokers funk and has rubbed off the white paint down to the base metal in small sections.
12) There are to small metal toggle switches on the back panel that act as a high / low , why would any one want to turn a measly 12 watt radio even further down mechanically , over just tuning it for a nice low dead key with a bit of swing !
Unlike the Stoner which pissed me off and had me worried that it may never run right or run again because of such lack of information. This Tram is fully documented , they are all over the place and I have a factory maual , a CD and You guys to tell me what a P.O.S my MexiTram is ,lol.
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Post by rifleman on Mar 17, 2011 17:28:15 GMT -5
Well, you cant say you were not warned, Steve !!!
First, a few things you should do BEFORE you get into the D201A....
Make sure that the fuse in the back is no larger than 4 amps !!!
And the fuse on the chassis on the side by the transformers should be a 1 amp !!! (People do crazy things !!!)
Put a new relay into it. They are not that expensive, and are a cause of a lot of problems.
Clean the tube sockets and tube pins with a good contact cleaner such as DeOxit. Again, many problems can be solved by that.
Have a full alignment done to the radio. A lot of the circuits interact with one another. It's the only way you will have a good starting point to seriously work on the radio !!!
I will go over some of the other problems you are having and post them later....
Ron
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Sandbagger
Administrator/The Boss 
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Post by Sandbagger on Mar 17, 2011 18:37:33 GMT -5
As You nice folks here know I have been wasting my money on, ah ah I , I mean "investing" , Ya investing my money in to old SB - CB gear, ;D lol. So I got a D201-A MexiTram in average to fair condition. It is working , I am using for the last 3 days. We checked all the tubes, most say 'Tram' right on them and we checked them with a checker and they do not leak , no shorts , they put out better than 100% so tubes are all good. Me and my technician buddy have never had one and so we wish to probe the minds of radio genius and generosity here for some guidance. We found a bunch of problems, such as the small vertical board ( BA board ? ) that is new or new'er was loose causing a horrible 'pop' noise with any slight vibration on the or around it, so we probed the radio with a plastic screw driver and isolated bad solder joints, we soldered that small board from the bottom and cured that problem. 1) There is a "hum" from the transformer , darned if that is not the the same musical note of hum that the commercial 480 volt transformer in the panel room next door make, lol, so we are wondering if the large aluminum looking caps next to it can be the possible reason for transformer hum as my tech suspects it is. The TX power is fine, the lights do not flicker or dim, it just hum-mmmmm's, so in a quiet room it will drive a person nut's, lol. 2) The crystal -channel section is way off, so when I select ch 38 / 27.38.500 via the channel selector it is actually on 27.383.63 , it is so far off that it is useless to even try and use the crystal channel section. I did notice that the crystal-channel switch is the newer black one. 3) In VF0 , the TX and RX are different , so to me they are not 'in sinc' and so I hear a good tone from my friends talking to me but I send a high off freq signal to them. Note: I sort of neutralize the clairifier, what I do I set the califier to 12 o clock 'before' I even tune the VFO, but once I do this and after a min I have to tune the clarifier again clock wise all past 3 o clock in order to tune incoming signals. 4) The VFO in passive receive drifts up, my buddy is on a rock solid Kenwood we use as test for being 'on freq', that and I turn my Kenwood on and turn turn down the rf gain and speak to myself and I find and after letting the Tram sit and warm up for 30 min it still wants to creep / drift up in freq a bit over a 20 min time period, not much but it does. I am willing to accept this as normal old tube radio issue but wonder if this will turn into a Siltronix super drifter if I don't take care of some sort of alignments that may need to be done ? 5) the VFO reads 39 when I am actually on 38, is this mechanical mis-alignment or electrical or both ? 6) Bleed over: This Tram has some of the worst adjacent channel rejection of all my radios. Local truck drivers passing by blow out my Tram . I am always on 38 LSB , they are always on 15 or 17 AM and I am getting killed by them. My Stoner almost completely eliminates any bleed over, so the Stoner sets the bench mark for rejection of unwanted signals. Is a Tram in need of something to help with nulling bleed over, should we check something ? 7) The meter is sluggish, on my other radios the meter swings with my modulation fast and furious, the Tram meter moves in s-l-o-w m-o-t-i-o-n on both TX and even in RX. 8) When You key up ( I am using a amplified D104 turned down for a clean audio) sometime, again 'some times' the meter the second You key up it swings far over to the right ( pegs in the Red ) then drops back after a split second to about S3 / 1 watt and that is the average base line were it fall back after a breath / pause in my audio. 9) There is a 'pop' when I key up coming through the speaker, this is instantaneous along with the normal relay 'click' , so i have a normal relay click and an electrical 'pop' through the speaker. 10) The speaker is original and seems to be dry and lacks fidelity, what speaker brand, dimensions and ohm should I replace it with ? 11 ) Cosmetically, does any one make stick on over-lay's for the face, because the white lower section of the face is dull smokers off white, and someone has used a harsh cleaner to take off the chain smokers funk and has rubbed off the white paint down to the base metal in small sections. 12) There are to small metal toggle switches on the back panel that act as a high / low , why would any one want to turn a measly 12 watt radio even further down mechanically , over just tuning it for a nice low dead key with a bit of swing ! Unlike the Stoner which pissed me off and had me worried that it may never run right or run again because of such lack of information. This Tram is fully documented , they are all over the place and I have a factory maual , a CD and You guys to tell me what a P.O.S my MexiTram is ,lol. Wow, you sure have a list there...... Unlike the Stoner, which I've never even seen other than in pictures, the Tram, I have had some experience with. Honestly, after restoring a half dozen of them, and seeing the same old issues, I've come to the conclusion that while the Tram was engineered for high performance CB'ing, the design is not a good one for longevity. The Browning Eagle wins that battle.. Anyway, let's see what I can say about your list of issues.... First off, the "black" channel switch is the old (bad) one. The Gray one is the newer (good) one. Your frequency problem is likely the fault of crystal drift. The D201A is the only 40 channel radio, that I'm aware of, that doesn't use a PLL, so consequently, you will have the same crystal drift issues as the 23 channel radio. The VFO transmit mod was probably done incorrectly, which may account for your issues with it. The clarifier should not work in the VFO mode, so if it does, somebody did something hokey when they modded it. As for VFO drift, yes they do drift. There's not a whole lot you can do about it. A lot of times they will drift when transmitting due to a small drop in filament voltage when transmitting. The transformer hum is probably due to loose transformer plates. If the can capacitors are not heating up (which would indicate resistance), then I wouldn't worry about it. You could try tightening up the transfomer bolts. Your excessive bleedover issue is interesting, as one of the Tram's most touted features, back in the day, was its superior adjacent channel rejection. My D201 seems to be very good in this regard. But like most with radios, if you have the noise blanker on, it makes the bleed from stong local splattery signals much worse. The "pop" in the speaker, when the relay switches from TX to RX is normal. I have several radios with relays in them that pop when you unkey. I guess making and breaking the audio transfomer creates a kickback voltage spike which causes the "pop". But it sounds like youwill need to go through the radio and make sure the VFO mod is done correctly. Then it will need a frequency alignment, and it wouldn't hurt to go through the whole radio. |
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Post by SteveInOregon on Mar 17, 2011 19:56:43 GMT -5
Oops I got the channel selector color wrong, so I have the crappy one, oh happy me, I got a 30+ year old channel selector that was spouse to break 30 + years ago  lol. Ok guy's, thanks for the pointers. I suspect there will be a few more guys who may wont to pop a reply over and give me hell, ah I mean hell-p , lol, funny what a 'p' does ot a bad situation , lol. The difference between a halo and a noose is only 6 inches,  lol. New Issue: News flash, this just in , issue # 11 > When I turn the squelch / feather it to the edge of the quite threshold the VFO lamp flickers like crazy , wazz up wit dat ?  So we are going to as per You advice: 1) Clean all tube sockets. 2) Tighten the transformer down. Read the factory manual and watch the CD. 3) Check and replace all caps ( standard cb 'should do' ) 4) Attempt an alignment by 'ear' by listening and transiting to a solid Kenwood HF rig as we only have an O-scope, no freq counter, and no signal generator. Failing that we will hand it off to our television shop owning extra class ham who builds his own radios aka Elmer who does have an super HP freq counter, sig gen etc.... to 'just fit ' , 'dont cal me till it's like new lol. Failing that then give up and send it off to Barkett , lol. PS: the relay "looks" new. ( for what that worth ) |
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Post by rifleman on Mar 17, 2011 22:23:16 GMT -5
I agree with Sandbagger 100%.... (I have had loose Tram transformers also)
A couple of things though.....
Doing an alignment "By Ear" (the classic Tram "Golden Screwdriver" treatment) on the radio is impossible, and will screw it up even more. A LOT of the components are used in other circuits, and they have to be adjusted in the right order (ie. tune the receiver by "ear" for max, and the transmit goes south).
When you have the time, get a good strong light and a magnifying glass. Go over every square inch of the circuits, looking for burned or discolored components, burned traces, discolored boards, cold or lifted solder joints, etc. (It's amazing what the heat does)
If you are going to keep the radio, find out what was done to the circuit for that "Power Switch", and return it to stock. (I have explanations for a few of the mods that were done to those radios in case you need to "reverse engineer" it)
Even when new, these radios drifted a bit during warm up. Especially when using sideband, giving the radio 30 minutes to settle down is a good idea.
A good receiver alignment may help your "Bleed Over" problem. And who knows what you may find. Maybe a "genius" did something to "improve" the receive.
No one that I have seen makes a "Sticker" for the front of the radio. And BTW the normal color is an off-white that looks "Smoked Up".
A lot of the tubes are the same type. Do not mix the tubes around. Especially the receiver tubes. It will change the radio's alignment.
I will have to look at the circuit to get some idea about the Squelch/Lamp problem.
U400, the UA741TC Op-Amp IC (Meter Amp) sometimes is one of the problems with the "S" meter. If you replace it, unsolder the old one and replace it first with a 8-pin IC socket. So in case you have to replace the IC again, it is just a plug-in.
Oh, and don't worry to much about the channel selector. Once you get the VFO working correctly on transmit, you will be using that most of the time anyway.
Have fun Steve !!!
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Post by SteveInOregon on Mar 17, 2011 22:37:52 GMT -5
Okee Dokee R M, i will not attempt to do a 'by ear' alignment I will bring it over to my Elmers bench .
And yes, I am use to a VFO on my Kenwood so its not that bad to not have a channel selector.
Thanks & TTYL
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Post by rifleman on Mar 17, 2011 23:03:21 GMT -5
I added a few things to my last post that you may want to see, Steve.
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Post by rifleman on Mar 18, 2011 3:06:12 GMT -5
Steve, I scanned in an article I had about changing out capacitors in the D201 / A radios. It may help your tech on what to look for.... Enjoy Attachments:
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Post by SteveInOregon on Mar 18, 2011 14:39:14 GMT -5
Steve, I scanned in an article I had about changing out capacitors in the D201 / A radios. It may help your tech on what to look for.... Enjoy Very Good, RM can You send this PDF over to my yahoo Email as I would like my tech buddy to read it before we start re-caping it. I don't know if You found this article within Grumpy's or outside on another site or ? For what ever reason I don't know how to import it to my Email from theis forum thread. I tried to see this post as an un-registered guest and cannot see it so he would not be able to see it here. PS: I did a re-read and dig what you are saying. TY RM |
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Post by rifleman on Mar 18, 2011 15:33:36 GMT -5
Sent....
I did not get it from here, but someone here may have posted it before.
I have had a printed copy of it for years.
If you don't get it, let me know.....
PS..... I have maybe 20 printed pages of known mods for the D201/A's.
Give me a day or two to scan and assemble them together. They may help you to "Reverse Engineer" some "Mystery" wiring you may have in your radio.....
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Post by SteveInOregon on Mar 18, 2011 19:24:45 GMT -5
Sent.... I did not get it from here, but someone here may have posted it before. I have had a printed copy of it for years. If you don't get it, let me know..... PS..... I have maybe 20 printed pages of known mods for the D201/A's. Give me a day or two to scan and assemble them together. They may help you to "Reverse Engineer" some "Mystery" wiring you may have in your radio..... Cool, My radio tech buddy says the twin small metal toggle switches on the back shocked him when he was switching them back and forth , so ya it would be nice to get rid of them. Thanks, any info would be appreciated much-o |
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Post by Deleted on Mar 20, 2011 11:57:34 GMT -5
That one line about replacing a 40uf with 4-10uf is pretty funny. It is much easier to just use a single 47uf. It is common practice in boatanchor society that the non-common cap value be replaced with the current common value, which in the case of 40uf, is 47uf. It will not change any of the function of the radio.
I recapped on of these for my friend, and it was brutally easy. The most important thing is to remember that the voltage is the value that you want to at least match, or step up. The uf value is perfectly fine to just use the next common value.
Common value examples (common value on right):
20uf - 22uf
30uf - 33uf
5uf - 4.7uf
40uf - 47uf
50uf - 56uf
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Post by SteveInOregon on Mar 21, 2011 18:26:35 GMT -5
After replacing some mall cap's in that little virtical board next to the big PA tube, we are going to remote mount it as You guys said it is to close to that big hot tube.
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Post by rifleman on Mar 22, 2011 1:09:33 GMT -5
I have seen a few of those "BA" boards looking like a blowtorch was put to them !!!!
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Deleted
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Post by Deleted on Mar 22, 2011 7:57:54 GMT -5
The one I re-capped was new. However, the other boards were smoked. Mine looked like it had been gone over by Barkett it such, many years before. Many of the power resistors were lifted off the board by the distance of a "pencil thickness", so as to dissipate hear better.
While these D201A PCB style radios sound superb on the air, they are of horrible design, especially with respect to heat dissipation. I was so stunned, that I recommended the owner to sell his, which he did. These may be good for people that do their own work. But for people that rely on repair shops, these radios are money pits.
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Mar 22, 2011 8:34:50 GMT -5
While these D201A PCB style radios sound superb on the air, they are of horrible design, especially with respect to heat dissipation. I was so stunned, that I recommended the owner to sell his, which he did. These may be good for people that do their own work. But for people that rely on repair shops, these radios are money pits. That's a pretty good synopsis of the D201. They are great performers, but if you have one that was someone's daily driver for 30 years, it's going to have a lot of "wear". Far more than comparible period pieces. The D201's design, from a signal perspective, is superb. But they cut corners on power supply design, and the excess heat was the result. It would probably have faired better if they had kept the original point wired layout. PC boards just don't handle excessive heat for long periods of time. |
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Mar 22, 2011 8:49:27 GMT -5
Sent.... I did not get it from here, but someone here may have posted it before. I have had a printed copy of it for years. If you don't get it, let me know..... PS..... I have maybe 20 printed pages of known mods for the D201/A's. Give me a day or two to scan and assemble them together. They may help you to "Reverse Engineer" some "Mystery" wiring you may have in your radio..... Cool, My radio tech buddy says the twin small metal toggle switches on the back shocked him when he was switching them back and forth , so ya it would be nice to get rid of them. Thanks, any info would be appreciated much-o Chances are good, that these switches bridge across one or more of the plate voltage dropping resistors. The D201 is capable of putting out more than 10 watts of carrier power and the modulator can support it at that level as well. But it's not as "punchy" as it is when left at the stock 4 watt level. It also increases the heat generation. For those reasons, I recommend removing power mods, let the radio bark at 4 watts and if you need more signal, a nice class AB amp will do the trick. |
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Post by rifleman on Mar 22, 2011 10:32:54 GMT -5
Printed circuit boards are great.....
Tubes are great....
Hot tube sockets and their resistors mounted on printed circuit boards S#%K !!!
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Post by SteveInOregon on Mar 22, 2011 21:01:41 GMT -5
We don't mind working on it, it's fun to work out the kinks and watch it get better and better.
The caps have all been replaced the transformer 'hummmmm' has now subsided.
The small vertical board next to the PA tube now as new caps and is now remotely mounted , now connected with long wire jumpers.
My tech buddy found a LOT of bad solder joint's all over the place.
He took out that honkytonk TX power switch combo that was installed at the back of the unit , the one that ~shocks~ you if you TX while touching it, and now put it back to stock .
He is cleaning all the channel selector contacts and pot's as they are all corroded.
Hey RM, You mentioned You have about 20 pages of mod's for the 201's ?
thanks guy's
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Post by SteveInOregon on Mar 23, 2011 0:13:04 GMT -5
accidental over post ;D Attachments:
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Mar 23, 2011 7:28:53 GMT -5
This is on the audio board, and we need to know what it does before we start turning it . On our factory schematic diagrams this tunable resistor does not show up, so is this an update from the factory and another Wilbur WannaBe additon that needs to go away ? Right not we have killer AM, but we don't use AM, and so we need to know if this tunes or aligns anything to do with SB ? There is no such pot in the 23 channel D201, however, it does not look like a "Sammy Screwdriver" mod either. I'm thinking this could be a bias adjustment. The later production D201A's switched from the fixed cathode bias which was used on all previous models, to an actual grid voltage bias. I've never worked on one of those, but if it is connected to the 6L6 output tube, be very careful how you set it, as you don't want to "cherry" the tube. |
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Post by rifleman on Mar 23, 2011 14:40:21 GMT -5
That is right near V603, correct ??
Does it look like it was added to the circuit board ??
It looks like it is located where R634 is supposed to be.
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Post by rifleman on Mar 23, 2011 17:20:27 GMT -5
Steve... I compiled all of the mods I could find on the Tram D201 / D201A radios. I sent 2 files to directly to you. (I had to split the file into 2 parts because of my version of Adobe Create. I will also put them up here, for anyone who is interested. Part 1.... Attachments:
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Post by rifleman on Mar 23, 2011 17:21:18 GMT -5
Part 2.... Attachments:
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Post by SteveInOregon on Mar 23, 2011 19:48:50 GMT -5
Great thanks RM.
Now as to Your questions ?> That is right near V603, correct ??
Does it look like it was added to the circuit board ??
It looks like it is located where R634 is supposed to be.
I will consult my tech buddy who has my Tram and the schematics to answer You 'if" you are asking me.
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Post by rifleman on Mar 23, 2011 20:01:23 GMT -5
Yes, that was in reference to your reply #19.....
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Post by SteveInOregon on Mar 24, 2011 21:09:06 GMT -5
Gotcha RM
So we have great AM, but the SB is not as clean as it needs to be and we are gonna install new tubes in that section, even tho the original ones marked "tram" test ok, we want to eliminate all possible deficiencies in order to get the SB sounding clean.
R M, can You pop over to my Stoner rebuild thread and read the questions that I just posted about it , perhaps You can shed some light on some remaining issues with the Stony.
PS: Were can a guy get the higher voltage caps on the internet for the MexiTram ?
Thanks
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Post by rifleman on Mar 25, 2011 10:02:32 GMT -5
The original multi-section can type caps are pretty expensive. I believe you can still get them from Barkett. But most people get higher voltage axial caps, bypass the originals (leaving them in place for esthetics), and mount the new ones under the chassis. This is where I get my caps from. Decent prices, and fast shipping. www.justradios.com/Hope this helps. PS... Remember, NO CB is going to work better on SSB than your Stoner !!! And Trams & Brownings are NOT known as great SSB rigs. AM is where they really shine !!! |
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Post by SteveInOregon on Mar 25, 2011 20:25:20 GMT -5
Yup, I am finding that it true the the Stony is my 'go to' SB'er. All the positives out weigh the very few neg as to make this radio the only CB-SB rig I would keep and never sell. The Tramy is sweet because toobs = boobs and we are toob men , lol. We did that "keep the old big caps on top and solder new ones from the bottom" deal so that is taken care of now. You guys were right the transformer was loose and now the hum is barely noticeable at all. TTYL |
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Mar 25, 2011 21:38:45 GMT -5
Yup, I am finding that it true the the Stony is my 'go to' SB'er. All the positives out weigh the very few neg as to make this radio the only CB-SB rig I would keep and never sell. The Tramy is sweet because toobs = boobs and we are toob men , lol. We did that "keep the old big caps on top and solder new ones from the bottom" deal so that is taken care of now. You guys were right the transformer was loose and now the hum is barely noticeable at all. TTYL Once in a while we get a few things right....  |
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lol.
lol.
