The Talking Machine Forum — For All Antique Phonographs & Recordings

ChuckA wrote:

startgroove wrote:To answer a previous question, the reason for offering two difference ballast tubes back then has to do with the line frequency and line voltage. UV876 is for a range of frequencies a little above and below 60 Hz, while the UV776 is for line frequencies below 50 Hz. (45 Hz was a line frequency that was infrequently employed in parts of the country back in the day. The lower line frequencies, when applied to a transformer that is wound for 60 Hz, don't allow as efficient a transfer of energy, hence the lower resistance of the UV776.)

Russie,

Can you post or point to the data sheet you are using to explain the function of the ballast tube in regards to its frequency characteristics?

As far as I know it's a simple current regulator that regulates the output voltage based on current draw, nothing in regards to the frequency of the incoming voltage.


Chuck

The lower you go in frequency, the closer the you get to direct current as the coil sees it.A coil wound for 60cycles (as these are)will draw more current on 45-50 cycles because the field hangs up longer before the next wave cancels it out.
therefore the ballast has to be rated to compensate for this

I would like to ask if any of you electronic gurus could tell me what might be holding my phono volume at one level. One machine at a medium level and another one at a lower level. I’ve cleaned up and verified good the two volume switches of the two offending machines. My VE 9-55 I’m keeping has no problem. I have eliminated the possibilities of all the components (Volume Seitch, Amp, Condenser Bank, Scratch Filter, and Radiola tubes) except the Radiola and the wiring harness in both of these two machines. My next step is to temporarily swap the Radiola between my VE 9-55 and one of the non-variable volume machines. Just thought I ask if you might be familiar enough to quickly point out where the problem may be or what to test. If it is in the Radiola, then my wild guess is that it is likely a bad capacitor in the Catacombs.

If you have an audio signal tracer, or an oscilloscope, it would be a big help toward tracing the problem through. With either, you could follow the signal and see where it is and what it is doing, and compare that with what it is supposed to do.

Meanwhile, I can offer a few general suggestions. Audio that is loud and does not change with a rotation of the volume control, indicates that the low side of the volume control is not making a connection to ground or the case. A quick and dirty way to check for that is too jump a low value resistor across the opposite ends of the volume control. If the volume drops, you have a good connection, if it does not, look at the volume control and its connections.

I don't know which amplifier you are referring to, but a quick look at an AP-997Y diagram shows that an input transformer is between the pick-up and volume control off the chassis. If there is a similar circuit on the amp in question, check the transformer and all connections for continuity. Cheers, Russie

Thanks Russie for the advice.

GOOD NEWS!!!! All three VE 9-55s are up and running perfectly, the AM, the phono, and the changer. Yay!!! The one that had a medium phono volume level was due to a mechanical issue which got resolved with adjustment. The one that had a low level phono volume was due to the pickup not being perfectly seated and hence the contacts where slightly off. In the process of troubleshooting these problems, all the switches and contacts were cleaned/lubricated in all 3 machines.

I will take pictures and videos tonight.

That’s really great news!

I’m a little bit behind you. I still need to get the power resistors changed out. Good thing I found out about that issue because the voltages are all off by quite a bit, using the originals - so it needed to go back for adjustments to those resistors anyway.

My latest achievement is to bolt big honkin’ 4” castors onto the thing (no suitable polluxes were available). Now I can wrestle it around easier and without carpet damage.

The buns are now about an inch off the ground. If you’re not looking carefully, the beast therefore appears to be levitating.

Correction: It wasn’t a poorly seated pickup that was causing the low phono volume. It was a bad pickup. I just realized I had swapped pickups and thought I had swapped them back. Who’s the guy that rebuilds these?

Btw, looking forward to hearing that your VE 9-40 is complete, Peter. You certainly are ahead of me on that machine. I’m going to do my 10-70s, 9-25s, and 8-60s before I get to the 9-40 and Borgias.

Here’s videos of two of the completed VE 9-55s showing its full operations:

Serial# 766 (sold):
https://youtu.be/CX8X5j5Fqog

Serial# 2061 (for sale):
https://youtu.be/en1AVgIRtpQ

Super cool!

Did the radios just work, or did you have to do any fixes to them?

Peter,

The Radiolas did not just work but were essentially easy fixes. The Volume Swirches needed to be cleaned, one had torn up wires on its wire wound ceramic tube resistor part that I swapped out. I also spray cleaned/lubricated the filament switch and the radio/phono switch as their contact points were quite dirty. The biggest thing was that there was a bunch of bad and weak tubes. To get 3 Radiolas’ worth of very good ones, I had to good deep into my supplies and other machines (9-40, Borgias, & Hyperion). What was strange was that there were tubes that passed my TV-10A/U tube tester’s mutual conductance tests but did not function when installed. I did a tremendous amount of verification of this. In the end, I had about 25 bad 199 tubes.

I am so happy I did not have to get into the Catacombs. The Scratch Filters for the phonographs also were good without any repairs.

I am anxiously awaiting an AM transmitter I purchased on eBay that will transmit the music I want to hear on a variety of AM frequencies.

Oh boy, does my Radiola 28 NOT like the transistor AM transmitter, but it does like the tube transmitter I had for some reason. Good luck with that one Wayne. The tube one that I have picks up a lot of 60 cycle hum for some reason and I've asked the guy that sells them on ebay why, he had some thoughts, but that's as far as it went with him and he stopped trying to trouble shoot that one. So I gave it to another guy to see if he could figure out what the deal is with the tube one.

I wonder on that transmitter if it transmits on too narrow of a bandwidth for the 28 to be happy with. There is a compression knob on the transistor one that I have, but I never messed with it that much. I have other radios around here that are a lot easier to tune.... They look nice Wayne, you did a good job on those things. Earl.