[AMRadio] Re: RCA 1:1 mod xfmr

Mike Sawyer w3slk at hughes.net
Sun Dec 2 00:20:48 EST 2007

If its the one I'm thinking of, I have one of those. It has a tertiary 
winding for the screens and a funky secondary max. I of 0.193 A(?) The one I 
was looking for but needs repaired is 10300 Pri. and 4300 sec. If memory 
serves me, it was used in a KW transmitter. Mine goes in my RCA ET-4336F 
transmitter. A rig that uses 813's X 805's for 250 watts, (very lightly 
----- Original Message ----- 
From: "D. Chester" <k4kyv at charter.net>
To: <amradio at mailman.qth.net>
Sent: Sunday, December 02, 2007 12:02 AM
Subject: [AMRadio] Re: RCA 1:1 mod xfmr

The RCA 1:1 ratio mod xfmr @ 5500 was made for liberty ship transmitters
during WW2.  It was not designed for voice, but for MCW, so it was meant for
running a single tone, and is not  high-fidelity.  That's why its audio
quality is on par with the  lowest cost "ham radio quality" modulation
transformers, nowhere as good as RCA broadcast modulation transformers.  The
quality  is quite acceptable if you are not looking for hi-fi audio.  With
the 1:1 ratio, you should be able to get incredible positive peaks.  The
properties of the transformer, as listed on the name plate, do not make
sense if you calculate using ohm's law, that is, current through the
secondary vs total power rating vs nominal impedance values.

Don k4kyv

More information about the AMRadio mailing list

This page last updated 17 Dec 2017.