[Johnson] Ranger keyer problem

[Roy Morgan]

At 11:06 PM 10/22/03 +0000, you wrote:

>Incidentally, the two 1614 modulators test quite weak and with a "life" test
>that drops.

Phil,

These 1614's are a problem.. they are expensive to buy if you don't have 
any (AES price is $30).  One possible substitute is the EL-34/6CA7 tube 
being currently manufactured at prices of about $12 each.  The guitar guys 
and gals use lots of them.  There are two considerations:

1) Filament current. I just don't know if the EL-34 takes more filament 
current. It may.

2) Slightly different pinout.. the EL-34 *may* have a separate connection 
for the screen on pin 6 (I think it does).  You'd need to clear any 
connections on that pin being used as a tie point, and wire the pin to the 
right place (cathode, I assume).

The current manufactured Tesla EL-34's are extremely rugged and I'd expect 
them to perform very well in the Ranger.  I do plan to look into this idea 
when I restore the Ranger I have here.  My Ranger has a kaput modulation 
transformer and burned tube sockets. It will get a replacement transformer 
I found, and ceramic sockets. This will let me make substitutions for the 
tubes as needed.

I'd be glad to hear any ideas or more facts you may have on this.

Roy


- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
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Home: 301-330-8828 Work: Voice: 301-975-3254,  Fax: 301-948-6213
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