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

Model 60 6A7 oscilator distortion
#1

Hello. I have a Model 60 run 7 that has been re-capped, re-resistored, and ant coil rewound. It has low sensitivity and is noisy below 650 KHz. Looking at the 6A7 oscillator waveform using a non-contact probe on an oscilloscope shows considerable distortion and and about a 5:1 attenuation of the signal as the radio is tuned towards the higher frequencies. A check with a spectrum analyzer shows multiple harmonics of the oscillator fundamental present. Is this distortion and attenuation normal? What might be the cause? It does not seem to affect the quality of the reception at the higher frequencies. I have tried two different "good" 6A7's with the same result. The radio works fine at frequencies above about 650 KHz. Thanks.

-Bill Kushner
Arl.Hts IL


Messages In This Thread
Model 60 6A7 oscilator distortion - by koosh01 - 11-28-2018, 03:53 PM
RE: Model 60 6A7 oscilator distortion - by AI2V - 12-29-2018, 04:55 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
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
Philco Model 16 wiring question
Thanks Morzh. So it appears I did wire it incorrectly and I have to switch the wires between pins 2 and 4.bobclausen — 09:24 AM
Philco 46-1209 strange behavior
No, it's not a problem, just during certain condition it could show up. Yes, an internal tube short could do that too. ...morzh — 09:13 AM
HiFi (Chifi) tube amp build - but my own design.
You sound guys are never satisfied. :crazy: :clap:RodB — 09:10 AM
HiFi (Chifi) tube amp build - but my own design.
I got some new ceramic octal tube sockets installed and also tried some different coupling caps.  The results:  The go...TV MAN — 08:42 AM

[-]
Who's Online
There are currently no members online.

>