[Collins] 30L-1 More questions

[Eric Moore]

OK guys, I am finally making progress on it. =20

Found a a wiring error on the B+ line.   It was bypassing L13 and C34, =
go figure.  So we looked really hard for any other novice repairs and =
did not find anything else.=20

It load's up, but it's really touchy tuning, something is still not =
right, although we did get it tuned up on 75Meters.  It had around =
600Watts output.  We did, however, burn up a 100 Ohm Suppressor Z2. The =
tubes get hot in 5 secs when not tuned with very low drive.  We suspect =
that the tubes may be a problem as the top set runs a dull red when just =
keyed up without any drive.  We switched them to the lower position and =
the same two tubes still glowed dull red, even in different sockets. =20

I guess my questions are as follows.

1.  When keyed, the bias supply goes to around -10VDC.  Is this OK?

2.  It sounds like my tubes are not matched.  How critical is that?  I =
am thinking about getting a set from RF parts the Taylor 811A's and =
wanted to know if you guys used those before?  Or should I just go with =
K5SVC Cetrons, although I do not believe he matches them.  I don't want =
to buy new tubes if the amp still has trouble. =20

The amp currently has JAN 811.  I know they are not 811A, but we should =
at least get the ampo to run on these, right? These are from the 1944 =
and they look the same.  Any ideas why 2 of them glow red when keyed =
without any drive?  Maybe some type of oscillation?

Any other ideas would be greatly appreciated.

73,
Eric
K8CCA


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