[AMRadio] re:transformer info


John coleman wa5bxo at gmail.com
Tue Nov 25 16:03:21 EST 2008


200uf is typically not enough capacitance for proper Q on 80 mtrs (maybe not
even 40 mtrs) even in and AB linear let alone class C so my guess is that it
had some fixed capacitors that got switched in to circuit to add to it.

 

John

 

-----Original Message-----
From: amradio-bounces at mailman.qth.net
[mailto:amradio-bounces at mailman.qth.net] On Behalf Of Brett Gazdzinski
Sent: Tuesday, November 25, 2008 12:53 PM
To: Discussion of AM Radio in the Amateur Service
Subject: Re: [AMRadio] re:transformer info

 

Hello all.

I got a deal on ebay, it looks like some sort of amp or transmitter with a
built in power supply, not sure what exactly it was supposed to do, it has a
socket for a 4cx250b type tube, a big loading cap, a bunch of octal sockets,
rectifier tubes, driver, exciter?

 

The power section has a transformer, grey, square, solder sealed, oil
filled, marked:

edo 06722

Acme T-14034

 

2850 volts center tapped, scratch70ma.

 

I am trying to find out the current rating as the scratch is right on the
number.

it looks to big for 170 ma.

The thing also has a nice round choke painted all black, no numbers, but it
looks like a utc CG102, only slightly smaller.

Its also got a 6uf 1500 volt oil filled cap.

 

I was hopeing to use the transformer to build up a seperate supply for the
mod deck of the 3X4d32 rig (811A's).

 

The voltage is right, 170ma would be a little light, 270ma would be fine.

 

A 4cx250 type tube could run at 250ma (peaks) at 2000 volts, in AB1 they
rest at 90 ma and get up to 250 ma.

 

About 200 pf in the loading cap, 160 and 80 meters, or 80 and 40 meters,
there was a switch, some parts are missing....

 

I got it for $45.00 and $15.00 shipping, its got 3 filiment transformers,
the HV supply, the 4cx250 type socket, some good power resistors, small adj
coils, etc.

The chassis was a hacked up mess, but it was wired ok for homebrew...

 

If anyone has any info on the transformer, please let me know, i looked
through old fair radio catalogs, which had most of the easy to get stuff
from way back...I did not see anything like it.

 

Brett

N2DTS

 

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