Without question, replace the power supply with something a lot heavier
and with more plate voltage than the original. Remember that it was
designed when the legal limit was about 40% (1000W INPUT) of what it is
now. However, if you run it at that level, it will probably last a long
time. I had the original power supply in one catch on fire while a
guest operator was working the Phone Sweepstakes Contest in about 1984.
Now have HB supplies with about 3600V and the amplifier puts out 1500W
with 100W or less drive. Good idea to put a muffin fan on the top
cabinet above each tube blowing up. Otherwise, you can cook breakfast
on the top cabinet.
Barry Kirkwood wrote:
>
> I used an L-4B happily for years with the original parasitic
> suppressors.
> I added a reduction drive to the plate tune capacitor. I also built a
> bigger and better power supply.
> The L-4B was an excellent performer and I only quit it for a model
> that had 160m capability.
> 73
> end
> Barry Kirkwood PhD ZL1DD
> Signal Hill Homestay
> 66 Cory Road
> Palm Beach
> Waiheke Island 1240
> NEW ZEALAND
> www.waiheke.co.nz/signal.htm
>
> ----- Original Message -----
> From: Jason Cooper
> To: amps@contesting.com
> Sent: Thursday, 01 February, 2001 8:59 AM
> Subject: [AMPS] Additional Tube Brand Question
>
> Hi All,
> I am about to re-tube my L-4B and have the same
> question concerning the 3-500Z. In addition, what mods
> are available for the L-4? I have read Measure's articles
> on amps and agree with the soft start and the glitch
> resistor. I plan to incorporate these when I
> change tubes and am also interested in other mods available
> for the L-4.
> Thanks in advance,
> Jason KN7AZ
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