BC-610 Mod Xfmr Diagram

[W7SOE]

Four connectors on one side, two on the other.

On the side with two connectors they are marked "P" and "B"

The top two on the side with four connectors are marked "P", the two on the bottom are marked "B".

Can anyone help me match the connectors with the windings?

Thanks

Rich

[W2PFY]

The two terminals marked (P) go to the plates of the modulator tubes. The two that are marked (B) are your B + line. You would run your B+ to the lower terminals and then from the B+ terminal's you would run a wire around to the other side of the mod transformer to terminal B. The other wire P will go to you plate final if your using a common power supply. If you are going to use two different power supplies, B+ will go to  B.   The modulated B+, (P) will go   to the final.

Is this clear to you??  

[W7SOE]

The two terminals marked (P) go to the plates of the modulator tubes. The two that are marked (B) are your B + line. You would run your B+ to the lower terminals and then from the B+ terminal's you would run a wire around to the other side of the mod transformer to terminal B. The other wire P will go to you plate final if your using a common power supply. If you are going to use two different power supplies, B+ will go to  B.   The modulated B+, (P) will go   to the final.

Is this clear to you??  

Being not that smart, I need a picture.  I will be using a single power supply.

How's this?

Rich

[W2PFY]

Rich, your drawing is right on the money. Glad you understood it

[W7SOE]

Rich, your drawing is right on the money. Glad you understood it

I am taking the rest of the day off!

[W2PFY]

Rich, I wonder if you checked out the windings with a meter?  Well, if you didn't, the reading from the mod side from B+ to each plate should be somewhat even but could be off one from the another by 20 ohms. The reading from P to P should be approximately twice as from B+ to a P. or about 300 ohms across. The B+ to P on the secondary should be about 135 ohms. Then you should put the meter in the highest meg ohm scale and read from primary to secondary and then from both sides to case ground. You should not get any readings but if you do and it's in the high meg ohm range, it should be baked out. An electric  motor repair shop oven or a very hot attic will dry it out. Do not operate the transformer until the readings are zero. I won't put it on a Megger until the readings are zero with an ohm meter. That's my story and I'm sticking to it

 

[W2PFY]

Some MO information from K4KYV

I was given a BC-610 modulation transformer this past weekend at Dayton, and need specs on it. I know the -610 used 100TH's, but have other tubes(HK254, 4-125's, 813's). Trying to find portion of the TM on the BC-610 that has the schematic.

It's about 20K plate-to-plate primary to 8K secondary.  The 610 runs 2000 volts at 250 mills to the final, making the modulating impedance 8000 ohms. The turns ratio is about 1.65:1, so the impedance ratio is just under 3:1. The transformer should be useful for any class-C load impedance between about 5K and  12k, provided the DC through the secondary doesn't exceed 300 mills or so.  Naturally the 3X load impedance will be reflected back to the modulator tubes.

Using a common power supply for modulator and final, with this transformer don't expect to get much over 100% positive peak modulation capability, because of the step-down ratio.  For higher positive peaks you will have to run higher voltage on the modulator than on the final.

Don k4kyv

[W7SOE]

That is all very useful info, thank you.

I did ohm it out and I saw exactly what you described.  I forgot to measure to the case I will have to do that.

Even better we have a hipot (Hiptronics) tester here at work.  Unfortunately I have no idea how to use it.  I am a digital guy, I hipot test to 1.8V DC.  ;-)

I have been trying to finds it's manual, no joy so far.

Rich

[W2PFY]

here you go, I never seen this before on line but I guess you could print it out.


http://www.scribd.com/doc/27679872/TM-11-826-Radio-Transmitters-BC-610-E-F-G-H-And-I-Radio-Transmitter-T-213-GRC-26-Antenna-Tuning-Units-BC-939-A-And-B-October-1952

[W7SOE]

That is all very useful info, thank you.

I did ohm it out and I saw exactly what you described.  I forgot to measure to the case I will have to do that.

Even better we have a hipot (Hiptronics) tester here at work.  Unfortunately I have no idea how to use it.  I am a digital guy, I hipot test to 1.8V DC.  ;-)

I have been trying to finds it's manual, no joy so far.

Rich

[N0WEK]

You should be able to find all kinds of manuals for the BC-610, both electronic and paper on Ebay for quite reasonable prices.

[KE6DF]

Here is an online manual:

http://www.scribd.com/doc/27679872/TM-11-826-Radio-Transmitters-BC-610-E-F-G-H-And-I-Radio-Transmitter-T-213-GRC-26-Antenna-Tuning-Units-BC-939-A-And-B-October-1952


*** Oops I see this was already posted ***

[KB2WIG]

R,

Nice paint job.... I painted my 610 mod xfermer black, in honor of the Derb.


klc