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Post by husker on Jul 10, 2008 0:06:19 GMT -5
You guys have been awesome with help on my Trams, now I have a few questions about my MKIII. First, when I bought it I didn't get a mic. But I have never seen the two hole jack..is that normal for the MkIII?? Also what does the "HF" mean and the HF Freqs on the transmitter dial?
thanks guys!!!!
(after I get this old girl running I am going to work on the MKIV I have )
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Sandbagger
Administrator/The Boss 
Posts: 6,247 
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Post by Sandbagger on Jul 10, 2008 6:22:23 GMT -5
You guys have been awesome with help on my Trams, now I have a few questions about my MKIII. First, when I bought it I didn't get a mic. But I have never seen the two hole jack..is that normal for the MkIII?? Also what does the "HF" mean and the HF Freqs on the transmitter dial? thanks guys!!!! (after I get this old girl running I am going to work on the MKIV I have ) Yep, that's the right mic connector. one pin is the PTT, the other is audio hot, and case shell is ground. "HF" is the reference for the upper channels above channel 28. Remember, when this radio was made, only 23 channels were legal. Anything above that was known as "HF" (The old term we used before the term "freeband" became widely accepted). The "HF" scale is shown below the channels on the MKIII receiver dial. |
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Post by BionicChicken on Jul 10, 2008 6:57:45 GMT -5
One thing on the mike connector.....be carefull. It has 110 volts on it. Of course it will let you know that also but I figured it might be better if I told you.
BC
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Post by Dr. Rigamortis on Jul 10, 2008 7:22:46 GMT -5
On the reference to the HF on the transmitter dial, the Mark III only transmitted on 1-23. It wouldnt transmit on the HF channels. It was legal to listen to HF, just not transmit there. It can be modified to transmit there, but if you have a Mark IV, just use it to talk on the 23-40 channels. Keep them as they were factory.. I have a couple Mark III's that are factory as you can get and I love them. When I want to talk to the locals on 35, I throw a switch, and I'm on my Mark IV. Easy peasy.
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Jul 10, 2008 9:19:55 GMT -5
On the reference to the HF on the transmitter dial, the Mark III only transmitted on 1-23. It wouldnt transmit on the HF channels. It was legal to listen to HF, just not transmit there. It can be modified to transmit there, but if you have a Mark IV, just use it to talk on the 23-40 channels. Keep them as they were factory.. I have a couple Mark III's that are factory as you can get and I love them. When I want to talk to the locals on 35, I throw a switch, and I'm on my Mark IV. Easy peasy. That's pretty much how I feel about all of my classics. Unless they were already modified for extra freqs, I leave them factory stock. Since I usually talk below channel 23, it's no problem to run any of the vintage rigs. If, for some reason, I need to go above 23, I have 40 channel radios to do the job. I think modifications to a vintage rig ruins much of the appeal. I have made some circuit changes when repairing old style rectifiers and filter caps. But those don't really affect how the rig plays. IMHO, to truly appreciate a classic radio, it should be as it was when it was made. |
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Post by husker on Jul 10, 2008 10:24:35 GMT -5
I agree 100000% I have plenty of other toys that go to 40 or whatever..I want to keep these old girls exactly as they are! I did notice that the receiver is WAY more sensitive then the Trams...I was hearing stuff with way better strength then i was with the Galaxy or even the Trams..Now I just need to find a Mic for this old girl to see how she sounds.
Another strange question guys, one of my Trams 201's has these black hard case tubes in it. Are those the military types??
Again, I can't thank you guys enough for all the info I have received!!!!!
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Jul 10, 2008 11:57:11 GMT -5
I agree 100000% I have plenty of other toys that go to 40 or whatever..I want to keep these old girls exactly as they are! I did notice that the receiver is WAY more sensitive then the Trams...I was hearing stuff with way better strength then i was with the Galaxy or even the Trams..Now I just need to find a Mic for this old girl to see how she sounds. Another strange question guys, one of my Trams 201's has these black hard case tubes in it. Are those the military types?? Again, I can't thank you guys enough for all the info I have received!!!!! I would venture that those "metal" tubes are some sort of industrial or military equivalent. Interesting your remarks about receiver sensitivity. In my experience, the D201 has one of the hottest receivers out there. But age can cause the sensitivity to fall off. If you can't set the "S" meter for S9 with 50 uV of input signal before the adjustment pot max's out, that's a clue that there's something not quite right. My own Tram was like that, until I put all new receiver tubes in it. Before, the sensitivity was about average for a CB rig. But once I put the new tubes in it, I found out what an exceptional receiver really was. There are also some receiver resistor values that change due to long term use with maximum rated current running through them. Another D201 I'm currently restoring had all new tubes in it, but still the receiver was only "average". Then I found the 100K resistor feeding B+ voltage to the 5.8 Mhz crystal oscillator (V301B) had drifted up to around 1Mohm. This resulted in a weaker than normal oscillator output. Replacing that resistor put that receiver in the "hotter than hot" sensitivity category. It now hears down to the limit of my signal generator (.04uV). The Brownings are normally pretty good as well, but I haven't seen one yet that'll outdo a good working D201 on receiver sensitivity. |
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Post by BionicChicken on Jul 10, 2008 12:08:24 GMT -5
They are metal encased 6L6's. They will perform as their glass counterparts or least they have in my experience. Had a friend years ago who built an amplifier using 4 of them. Nothing on the top of the deck except the tubes. When he finished he would take a 5 gallon bucket of water and turn the deck over and let the 4 tubes set about 3/4 of the total length of the tubes in it. Hammer all night long...........the water would get hot but the amp never had any trouble. The funniest thing I ever saw was one time I was over there he had hot dog wieners in the bucket warming them up to eat. I guess kill the munchies and talk at the same time....what a concept!!
BC
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Post by Tombstone (R.I.P.) on Jul 10, 2008 12:59:01 GMT -5
Wow, that's crazy, sounds like electrocution ready to happen. Don't know the why of the metal tubes but I have some here in stock and a lot of old table radios and all of my military receivers have them??
Tombstone
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Post by husker on Jul 10, 2008 13:16:00 GMT -5
I agree 100000% I have plenty of other toys that go to 40 or whatever..I want to keep these old girls exactly as they are! I did notice that the receiver is WAY more sensitive then the Trams...I was hearing stuff with way better strength then i was with the Galaxy or even the Trams..Now I just need to find a Mic for this old girl to see how she sounds. Another strange question guys, one of my Trams 201's has these black hard case tubes in it. Are those the military types?? Again, I can't thank you guys enough for all the info I have received!!!!! I would venture that those "metal" tubes are some sort of industrial or military equivalent. Interesting your remarks about receiver sensitivity. In my experience, the D201 has one of the hottest receivers out there. But age can cause the sensitivity to fall off. If you can't set the "S" meter for S9 with 50 uV of input signal before the adjustment pot max's out, that's a clue that there's something not quite right. My own Tram was like that, until I put all new receiver tubes in it. Before, the sensitivity was about average for a CB rig. But once I put the new tubes in it, I found out what an exceptional receiver really was. There are also some receiver resistor values that change due to long term use with maximum rated current running through them. Another D201 I'm currently restoring had all new tubes in it, but still the receiver was only "average". Then I found the 100K resistor feeding B+ voltage to the 5.8 Mhz crystal oscillator (V301B) had drifted up to around 1Mohm. This resulted in a weaker than normal oscillator output. Replacing that resistor put that receiver in the "hotter than hot" sensitivity category. It now hears down to the limit of my signal generator (.04uV). The Brownings are normally pretty good as well, but I haven't seen one yet that'll outdo a good working D201 on receiver sensitivity. I have a funny feeling both my 201A'a need alot of love. But you really have to know where you have no business going and having me attempt to do any trouble shooting at the level you speak of would end up VERY bad...I know my limits  |
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Post by BionicChicken on Jul 10, 2008 17:02:52 GMT -5
Tombstone I think they were a military spec type deal. Haven't done a search on them yet but they work. Outside metal jacket is not connected to any of the internal workings. You can touch them while they are in use and feel the heat they dissapate.
I never really noticed too much difference between them and their glass counterparts but maybe if mil spec they are more rugged?
But regardless........................they will warm a hot dog up!!!!
BC
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Post by husker on Jul 10, 2008 21:36:24 GMT -5
 A pic of the Tram 201A's |
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Post by husker on Jul 10, 2008 21:37:56 GMT -5
 The MkIII All I need now is a Mic! |
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Post by husker on Jul 10, 2008 21:41:43 GMT -5
 And of course the 201's..... they still need some love. One radio at a time! |
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Post by 2600 on Jul 10, 2008 23:15:19 GMT -5
The metal-envelope tubes normally have an "octal" base. The one with the fat plastic keying pin sticking out of the center of the tubes base, and eight chrome-plated pins around it.
The metal envelope is normally connected to pin #8. Pin 8 in the metal 6L6 is connected to the cathode, so there would be thirty Volts DC or so on it in a D201. Not really a shock hazard. The metal-octal tubes were used in a LOT of WW2 military stuff. Never have found out if this was a specification for ruggedness. But these tubes were developed before WW2 in the 1930s by RCA, I think.
The power rating for the metal 6L6 is lower than for the glass versions. More heat will radiate through the glass than you can dump through the steel envelope. Tube types that were first marketed in the metal envelope were mostly sold also in a version with a glass envelope and the normal hard-plastic base. You would see the letter "G" following the type number to indicate the "glass" version of a tube first sold in the metal envelope.
But the "6L6GC" is the most recent glass version. The final suffix letter "C" just means that this tube was revised (spell 'improved) three times. It's rare to find a "6L6GA". The "6L6GB" has a smaller glass envelope and will fit places that the final "C" version won't go. But the smaller envelope reduces the power rating, compared with the larger "C" version.
There are also "industrial" versions with four-digit type numbers.
6L6GB is a 5881.
6L6GC is a 7581
73
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Post by Dr. Rigamortis on Jul 11, 2008 7:17:04 GMT -5
While we are talking about tubes for a second, What is a good replacement...if there is any...for a 5763 for a Golden Eagle Model B, or for a 7558 for the Mark III and Mark IV? And as a replacement I am looking for somethign with a little more "spunk". I think the 7558 is a 30 watt tube, but of course you cant get that from an old bird without doing some dirty work underneath.
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Post by BionicChicken on Jul 11, 2008 7:27:59 GMT -5
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Post by BionicChicken on Jul 11, 2008 7:46:53 GMT -5
Can't remember any subs for the 7558. I have seen the 5763 replaced with a 7558 via an adapter socket wired so it would fit. Seems like it did a little better than the stock tube. Of course there is always the old tricks of jumping resistors or adding a neon bulb across them to get more dead key or swing but then you put undue stress on other parts. Most folks around here would run a JB 150 or Mini Scout with the Brownings and that was "barefooted".
BC
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Post by 2600 on Jul 11, 2008 14:46:16 GMT -5
I stand corrected about pin 1. Pretty sure you were supposed to ground pin 1 on the metal tube.
73
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Post by husker on Jul 11, 2008 16:24:21 GMT -5
I will post a pic of the tubes so you guys can see them if you want
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Post by Dr. Rigamortis on Jul 11, 2008 18:20:07 GMT -5
Ya, thats why I said you could do some dirty work in the bottom, but I dont like jumpers. I was just thinking there would be a little hotter tube, maybe 2-4 watts more with out having to do some modifications.
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Post by BionicChicken on Jul 11, 2008 22:02:12 GMT -5
Grounding pin 1 would probably be a pretty good idea. It wouldn't be a hazard unless something shorted to the case and then you would have more problems to deal with than just the shocking hazard.
In some radios the metal tubes work better than the glass ones or at least to what I have seen....but not in all of them.
Maybe now a days they would just be better suited to warming hot dogs. Since I thought about that I have almost talked myself into building at least a two tuber to use like that. Many folks around here would get a kick out of it. They only think transisitors are all that does the job. It seems I saw a project 6 meter amp with a 6L6 that was water cooled like that. Maybe that will be a start.
BC
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Post by BionicChicken on Jul 11, 2008 22:06:57 GMT -5
The neons work well but as some have stated they just make the meter happy. With the few watts gain you get it's just a judgement call on whether to do it or not. But they do work.
The thing about Brownings I have seen is they won't talk the wattage that a Tram will but will drive an amplifier harder. I'm just wondering if others have noticed this also. The Mark III's seem to drive an amp to higher output than just about any other radio including the black radios that I have seen.
I see someone has the statement that " Happiness is a warm tube". I couldn't agree more.
BC
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Post by 2600 on Jul 11, 2008 22:34:40 GMT -5
The one "hotter" sub for the final in a Browning AM-only transmitter that I know is the 6GK6.
The socket has to be partly rewired. Seems to me that adding a parasitic choke may have been necessary on some radios, and a different value for the screen resistor, too.
But it never got organized as a "procedure".
But it's a hotter tube with at least the same power rating as the 5763.
I have seen the 6CL6 used this way, but every one I saw wanted to oscillate. I don't consider this tube a good candidate.
73
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Jul 12, 2008 10:29:56 GMT -5
The neons work well but as some have stated they just make the meter happy. With the few watts gain you get it's just a judgement call on whether to do it or not. But they do work. The thing about Brownings I have seen is they won't talk the wattage that a Tram will but will drive an amplifier harder. I'm just wondering if others have noticed this also. The Mark III's seem to drive an amp to higher output than just about any other radio including the black radios that I have seen. I see someone has the statement that " Happiness is a warm tube". I couldn't agree more. BC The 6L6GC tube in the Tram is capable of a bit more carrier power out than the Browning. But, I've seen Trams modified with a "Hi/LO" power switch, and to be honest, while putting out a 10 watt carrier might look impressive on a wattmeter, the modulation power is not enough to modulate it with the same punch as a stock 4 watt carrier. It just doesn't look as nice on the scope. I actually drop the carrier power on mine down to 2.5 watts and let the modulation swing. It's far more punchy that way, and the amp takes care of amplifiying the whole shooting match. I do the same thing with my Browning. |
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Post by husker on Jul 12, 2008 12:57:19 GMT -5
The neons work well but as some have stated they just make the meter happy. With the few watts gain you get it's just a judgement call on whether to do it or not. But they do work. The thing about Brownings I have seen is they won't talk the wattage that a Tram will but will drive an amplifier harder. I'm just wondering if others have noticed this also. The Mark III's seem to drive an amp to higher output than just about any other radio including the black radios that I have seen. I see someone has the statement that " Happiness is a warm tube". I couldn't agree more. BC The 6L6GC tube in the Tram is capable of a bit more carrier power out than the Browning. But, I've seen Trams modified with a "Hi/LO" power switch, and to be honest, while putting out a 10 watt carrier might look impressive on a wattmeter, the modulation power is not enough to modulate it with the same punch as a stock 4 watt carrier. It just doesn't look as nice on the scope. I actually drop the carrier power on mine down to 2.5 watts and let the modulation swing. It's far more punchy that way, and the amp takes care of amplifiying the whole shooting match. I do the same thing with my Browning. One of my 201A's has the Hi/Lo switch. It will go fro 3.5-4 on lo to over 10 on hi. After reading what many of you have been saying about pushing the radio and thinking of how old these girls really are, I figure pushing it that hard will do nothing but bring about an early death of the already worn out parts. So I never use the Hi setting... |
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Post by Tombstone (R.I.P.) on Jul 13, 2008 8:10:36 GMT -5
I had a Tram D201 with a high power switch and on the high side it would fry the relay so you're smart to stay on low power.
Tombstone
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Post by mark4 on Jul 13, 2008 10:01:57 GMT -5
I couldn't agree more with Sandbagger and Tombstone. If you want more modulated peak power out of a browning MarkIV. 2600 has a mod for this. What most people don't realize, the higher the carrier the less modulation.  GET A AMP! 2600's mod gives a little more modulated peak power. Without frying your radio. As for a Tram D201 they certainly don't need any help in this area. Some folks have a cow when any mod is done to a old classic. I understand this to some degree. But extra channels and some other mods are nice. As long as it can be put back to stock without any modification to the chassis. Strapping resistors is just plain stupid and hard on the radio. |
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Post by husker on Jul 13, 2008 11:46:50 GMT -5
Ok, guys I need some help with what looks like a huge receive issues with both my D201A's. Please keep in mind I am a beginner when it comes to working on radios. I have replaced v400 and v401, but the receive section is still very weak. I was reading about a specific resister that also needs to be replaced. If one of you incredabily smart guys tell me which one and what to use( where to find the actual new part) I will try to fix the issue myself. Ireaaly want to learn to work on these old radios and I will do the best I can if someone is willing to help me.
Thanks folks!!
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GET A AMP!