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FM 200-B modification from Vacuum Tube Valley magazine

KiM3Ce

KiM3Ce

AK Subscriber
Subscriber
First the good news:

Past issues of the publication Vacuum Tube Valley can be seen here:

HOME PAGE WorldRadioHistory Radio Music Electronics Publications

WorldRadioHistory: Thousands of Radio Music Electronics Publications ALL FREE
www.worldradiohistory.com

The bad news is there is no index.

I believe it was in that magazine I read about a modification for the 200-B. As I recall, the tuner has a cathode follower at the output, but many thought it sounded better with that bypassed. I see it on the schematic.

I found the Fisher history article, and the FM-100 article, but I think the article was an overall overview of the Fisher tube tuners.

If anyone can please point me to right edition of Vacuum Tube Valley, I would appreciate it! Thank you!
 
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KiM3Ce said:
First the good news:

Past issues of the publication Vacuum Tube Valley can be seen here:

HOME PAGE WorldRadioHistory Radio Music Electronics Publications

WorldRadioHistory: Thousands of Radio Music Electronics Publications ALL FREE
www.worldradiohistory.com

The bad news is there is no index.

I believe it was in that magazine I read about a modification for the 200-B. As I recall, the tuner has a cathode follower at the output, but many thought it sounded better with that bypassed. I see it on the schematic.

I found the Fisher history article, and the FM-100 article, but I think the article was an overall overview of the Fisher tube tuners.

If anyone can please point me to right edition of Vacuum Tube Valley, I would appreciate it! Thank you!
Click to expand...

Pioneering Wireless (Radio) - eMagazines

Vacuum Tube Valley emagazine is a modern publication, but many articles apply towards Pioneering Radio technology.
web.archive.org
 
I was close but not quite! In Issue 5, page 11 in the tuner shootout, the modification skipping the output stage was on the FM-1000, not the FM-200B. Thanks!
 
1707145248265.png

looks like this is what they removed

1707145075971.png

If the output level was too much I may have considered making the EF86 run in triode mode, or perhaps bypassing just that stage but leaving the cathode follower. I like the low output impedance you get from a follower stage.
 
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