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 Heterodyne whistle
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 Return to top of page · Post #: 1 · Written at 6:41:36 AM on 21 September 2008.
Simplex's Gravatar
 Location: Bathurst, NSW
 Member since 7 August 2008
 Member #: 336
 Postcount: 391

Hi there,
Have completed a rebuild on a Kriesler Model 11-91 stereogram for a friend. Works exceeding well but when tuning to radio stations get a annoying whistle. Particulary the local ABC station. This Kriesler has a ferrite rod as well as provision for a wire aerial. The receiver has a 6AN7 and 6N8.
Remember that there was a change to the spacing of broadcast stations on the AM band.
Believe that there is a mod that can be done to the front end to over come this hetereodyne.
Does anyone know what the mod is ?
Thanks for your help.

Cheers, Simplex


 
 Return to top of page · Post #: 2 · Written at 10:33:14 PM on 21 February 2009.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

Spacing is not the problem.
In last radio that I fixed with that problem it was the 6N8 used as detector and RF amp. That set was reflexed
I have no info on this set
There could be an IF alignment problem or incorrect voltages due to components failing or drifting in value


 
 Return to top of page · Post #: 3 · Written at 9:57:13 PM on 23 February 2009.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

Back again
There is an article relevant to this in Silicon Chip March 2009 "Vintage Radio" p82 - 87 Note the un-named valve in the mod to the Pilot, in the article, is a 6V6 set for 180V

Regards Marc

Check everything before modifying, or the mod may not fix it either.
ie. Read what is said: Rodney makes a lot of sensible & important comment. for those attempting to fix these radio's

Webmaster... wrong place I know, but the only email on the site, my system does not want to know.
EVATCO has been sold and has moved to Qld.


 
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