B&W 5100 No TX Audio

[w9bea]

Good Evening to the list:

I took possession of a really nice looking Barker and Williamson 5100 Transmitter.  Looks like it was well cared for; the electrolytics were all replaced with new modern ones.

At first I could not get it to transmit (meaning that I could not pull in the relay under the chassis).

I re-set the cinch jones plugs, pulled and tested the tubes, discovered that one of the rectifiers was loose in the socket, reset it, brought it up on the variac, and presto!  Relays were a-clicking and Was getting 100-115 watts carrier into a dummy load.

The problem now is no transmit audio... Not even some noise.  Turned the audio gain all the way up, no dice.

The CW position works fine (and has a darned good sounding chirp free note).  The VFO tune position works fine (although I hear some buzzing or laboring sound emanating from one of the voltage regulators). 

I hear the carrier sans audio on one of my station receivers.

I do not have a manual yet and I will order one from W7FG tonight.

In absence of a manual which I will buy, does anyone have any quick tech-tips of what I should be looking for on or in the radio?

Voltages, or the lack thereof?

Took my Fluke Laser Thermometer, and none of the transformer or choke bells were getting terribly hot.  I assume that this is a good thing.

On the terminal strip on the back (I assume that this is a breakout for a linear amplifier or a SBB Converter) There is a bare wire jumper on terminals 5 and 6; and another wire jumper on terminals 8 and 9.  I assume that the relay voltage for the TR relay is on terminals 1 and 2.  Am I missing anything?

I appreciate any guidance you might have to offer.

73--Wally W9BEA

[KB2WIG]

Go to the BAMA website and download a free manual...... im on the cellphone, so pasting the link is a pain........   google bama manuals and youll be cool.

Do it for the children,

KLC

[WZ1M]

Check for plate voltage on the modulation tubes. Dont need the manual for that. If no voltage, mod iron is toast.
Regards,
TRS
Gary

[kd1nw]

Hi Wally,

I've run into mic issues on more than one occasion. Is the mic known to be good? Wiring is okay or if its a D-104 has a working element in it?

Thanks 73
Kevin

[w9bea]

Good Morning:

1. I ordered the manual last night on the web.

2. I tried to download it from BAMA in advance of receiving a printed one; the computer would not trnslate it into a document.  It came out in gibberish.  Yes, I am comfuser challenged too!

3. The microphone is fine.  Works on my KWS1 and my Viking II.

4.  I measured with my fluke 289 True RMS DVM 650-660 VDC and roughly 200 VAC on each tube, front and back.  The meter lets be show both the AC and DC component on the screen simultaneously.

5.  THEN.... I appeared to fix it..... I re-seated the Cinch-Jones plug to the rear of the Modulator chassis again several times thinking that there might be some corrosion or something.  The TX Audio came back.  Rig sounds fine.

You see that? Every now and then, even a blind squirrel gets a nut I suppose.

Another question..... I see that one regulator is an OC3 and the other is an OD3.  The lettering is kinda faded but I am pretty sure that this is what it is....  What are the differences in the two, voltage output?  I assume that they are not interchangeable?  They look similar in appearance, and I suppose the uninformed could seat the wrong tube in the wrong socket.  I might put a few of these tubes on my shopping list as I do not have any spares. 

I have plenty of 6146's both A and B models; and a few 6AQ5's on the shelf.

One of the dial lights is dead, so I'll need to replace that when it cools off.  Guess that is a #47 bulb?

Is there any other high-failure components that I should seriously look at or at least ensure I have spares of?

Appreciate the insight....

73--Wally W9BEA

[n2bc]

Hi Wally,  Congrats an getting the B&W going.   Many of the manuals on BAMA are in "djvu" format.  Go here:
http://windjview.sourceforge.net/  to get a goodie to view & print this format.
73, Bill  N2BC

[kd1nw]

Congrats Wally,

For the VR tubes. The schematic has

V14 - 0D3 - 150V regulator
V15 - 0C3 - 105V regulator

Thanks 73 - Kevin