7B70 - Fixed


n4buq
 

I purchased a very inexpensive 7B70 in as-is condition. On arrival, it wouldn't trigger and I traced the problem to the first Tunnel Diode, VR304, (a 10mA TD) in the Trigger Generator. It appeared someone had replaced the original with possibly one of the Russian diodes. I replaced that with another 1S2199 (same as I used for the 10mA diode in my 7B53N a few weeks ago) and it triggers fine now.

Just thought I'd pass that along in case others find bad ones and are looking for replacements. These are for sale on eBay at a somewhat reasonable price.

Thanks,
Barry - N4BUQ

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