View Full Version : Wavy condition


bigaudioal
07-26-2015, 11:10 PM
Can anyone tell me what might cause this wavy condition? Have it on two of my sets. All other sets are fine. I broadcast with a blonder tonge agile modulator on Channel 7 frequency and all my vintage sets are set to channel 7 and just pick up the signal with vintage rabbit ears. Seems odd that only two of my sets do this. Not sure if it is the signal or the sets. Pilot is an electrostatic deflection set and the other set that does this is a Crosley 630 clone. Have tried swapping tubes in both sets. Everything else seems great on both sets. Any ideas?

Thx!

http://youtu.be/zis459ig8BY

WISCOJIM
07-26-2015, 11:45 PM
Looks like you've got a 60Hz hum bar, need to do more filtering.

.

jr_tech
07-26-2015, 11:59 PM
If you connect the BT directly to the TV antenna input do you still get the 60 hz hum waver?

jr

old_coot88
07-27-2015, 12:22 AM
B+ ripple from bad power supply filters in both sets is causing the bend. The slow creep is due to difference between vert sweep rate and power line frequency.
It can sometimes be accompanied by a dark hum bar that moves with it (if the ripple is getting into the video section).

bigaudioal
07-27-2015, 06:41 AM
Darn it! Just recapped the entire set. Maybe got a bad new filter cap???

DaveWM
07-27-2015, 07:22 AM
If you connect the BT directly to the TV antenna input do you still get the 60 hz hum waver?

jr

Did you try this yet?

zeno
07-27-2015, 07:39 AM
I vote for bad filter can. Check your work & the values.

since its on 2 sets try a different input also like
a DVD VCR etc. Also as said direct.

73 Zeno:smoke:

WISCOJIM
07-27-2015, 08:02 AM
If you added a CRT filament transformer to the Pilot, make sure the wiring for that isn't running where it could transfer the line hum.

bigaudioal
07-27-2015, 04:45 PM
I have not added a separate transformer for CRT filament. Just powering up very slow on variac now for testing after recap.

I have not had a chance to try and feed a direct signal into the set's antenna terminals yet. But will try this week sometime.