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
philcorepairbench.com - shadow-meter
Thanks Ron.fenbach — 02:43 PM
Model 70 Cabinet Trim
Thank you, Gary. Before making my original post, I had clicked on "Steve Davis Cabinets" only to find that it...musar — 02:25 PM
philco predicta
Welcome to the Phorum, cgl18! I am not your resource for television repair, but lots of friendly help is available here...GarySP — 02:12 PM
Model 70 Cabinet Trim
Welcome to the Phorum, musar! You can send Steve Davis a private message (PM). The site is at the top of the Home page...GarySP — 02:09 PM
Model 70 Cabinet Trim
How do I contact him? The only contact information for him I could find when searching online was a telephone number th...musar — 10:38 AM
philco predicta
Hello, good afternoon, I would like to ask what the possible problem could be if I don't have an image on the screen. I ...cgl18 — 10:19 AM
Philco model 38 code 121 not receiving signal.
So one last question before I finish this radio. Regarding the speaker and output transformer. I salvaged the original o...Stormlord5500 — 09:31 AM
462ron
It’s on the bottom of the homepage of our Philcoradio.com homepage! Ron462ron — 07:20 AM
Model 70 Cabinet Trim
Steve might have some trim left. Not sure he is making anything.morzh — 06:12 AM
Model 70 Cabinet Trim
Hello musar, First all welcome to the forum and yes that is true that steve stopped making trim . Sincerely Richar...radiorich — 12:13 AM

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

>