[AMPS] 6m amp

[Rich Measures]

>Oops --  some clarificaton needed.
>
>The load is 50 ohms, non reactive.
>
€  What is the resistance of your termination R when Measured with a DMM? 
.....thanks

>The coil is 3/8" tubing, not 5/16".  

€  ok

>Sorry for the confusion.  73,  Arliss
>
>Rich Measures wrote:
>> 
>> >
>> >Hi,
>> >
>> >I think the efficiency of my homebrew 6m 8877 amp is
>> >lower than it should be (currently about 50 %), and am
>> >looking for some suggestions on how to improve the
>> >situation.
>> 
>> €  What is the resistance of your termination R when measured with a DMM?
>> >
>> >The amp runs about 2800 V key down at 1 amp, with 50 mA
>> >of grid current, into a 50 ohm load.  Idling current
>> >(set with a 12V Zener) is about 75 mA.  The plate
>> >circuit is a Pi-L network patterned after Lauren Libby's
>> >(W0LD) HR article from July 1986, using a vacuum variable
>> >tuning capacitor, 3/16" copper tubing for the coil,...
>> 
>> €   Due to skin effect, the circumference of conductors needs to be
>> greater as f increases.  IMO, for good tank efficiency, 3/16" tubing is
>> ok for an 8877 on 160m.  For 10m, it is not.
>> 
>> -  later, Arliss
>> 
>> Rich...
>> 
>> R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures



Rich...

R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures  


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