Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Hammond Output Transformer Feedback Loop Workaround
#1

Hello,

I'm replacing a Philco output transformer on a 39-40. I'm wondering how to work with the center tap connection on the primary or where the center tap used to be as well the feedback center tap on the secondary. I did read an earlier post about taking the high side of the secondary for the feedback. I was little uncertain about going about it. Can anyone help me out. Thanks.
#2

The center tap on the primary side isn't going to do you any good for feedback as there is no audio present at that point just HV. The feedback loop will have to be connected to the secondary. I would just experiment with the different taps till you find something you like. I'm assuming that the transformer has a multi tap secondary. If it oscillates (squeals) reverse the connections. That's called positive regeneration what you want negative feedback or negative regeneration.
Good luck!
Terry

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry




Users browsing this thread:
[-]
Recent Posts
Rogers Majestic R-646
You can bypass the interstage transformer by disconnecting the primary, connect a load resistor of about 10k - 20k to th...RodB — 09:40 AM
HiFi (Chifi) tube amp build - but my own design.
So, here's Prince on stage halfway through Purple Rain when he stoops down to his tech and says "Rod, pull out that...RodB — 09:17 AM
Rogers Majestic R-646
Today I finished inspecting all the parts. The result is not very pleasing. The first positive news: 1) The power tr...Vlad95 — 11:40 PM
HiFi (Chifi) tube amp build - but my own design.
Well, found muh culprit. After using socket test adapters and finding voltages all ok, swapping 6V6s, no avail, swapped ...TV MAN — 11:18 PM
HiFi (Chifi) tube amp build - but my own design.
Well, maybe - maybe not  :lol: It's been an interesting project so far! Something so simple, yet so cranky. The 1st one ...TV MAN — 05:12 PM
1949 Motorola 5A9M
Haven't thought of Burgess batteres in a while  https://www.radionostalgia.ca/lib/Images/battery/us/burgess1D.jpgi ...Vlad95 — 03:50 PM
Philco Model 16 wiring question
Measure the voltages first, just in case.morzh — 02:19 PM
1949 Motorola 5A9M
Haven't thought of Burgess batteries in a while Mr. Fixer. Boston Edison always used Burgess in their Bright Star yellow...Paul Philco322 — 02:17 PM
1949 Motorola 5A9M
Thanks Sam. I'll let you know. I can probably scare some up from the local radio club.klondike98 — 02:07 PM
Philco 89 Code 123 Osc Coil
Hello,  I thought I would post my findings on my bad oscillator tickler coil. There were 27 turns on the outer coil b...dconant — 12:38 PM

[-]
Who's Online
There are currently 1011 online users. [Complete List]
» 3 Member(s) | 1008 Guest(s)
AvatarAvatarAvatar

>