>Power output with a tank that doesn't resonate? Not likely.
>
? In my experiences, a Pi-network output matching network is not strictly at
the frequency is is working on. For a Q of 10, resonance seemingly occurs c.
10% lower than the operating frequency. The reason for this is that a
Pi-network is simply two L-netorks back-to back, so it is more akin to a Z
stepdown transformer than a L/C resonant tank circuit with a pickup link.
>Have you used a GDO to find if the tank is actually resonant in each band?
>(And to find that hopefully the plate RF choke is NOT?)
>
? and if the plate/anode choke is resonant, it will promptly send up a smoke
signal.
>-WB2WIK/6
>
>"Success is the ability to go from failure to failure with no loss of
>enthusiasm." -Winston Churchill
>
>> -----Original Message-----
>> From: Ku4uk@aol.com [SMTP:Ku4uk@aol.com]
>> Sent: Thursday, May 22, 2003 9:03 PM
>> To: amps@contesting.com
>> Subject: [Amps] 4-1000 output
>>
>> Thanks to all who help me on this home-brew amp. Now that I have it built.
>> I
>> need more help. To start with. The tube was found on ebay. dont know if it
>> is
>> good are not. Dont have one to put in amp to see if it is the tube. Ok
>> this
>> amp is only built for 160, 80, 40 meters. Tank circuit is tuned to these
>> bands. No shorts are opens.in high voltage or tank. Antenna relay working
>> right.
>> Two 1000 pf 12000 volts blocking caps. Ssb resting plate is about 90 ma.
>> On
>> transmit I can turn drive up to about 400 ma plate & 200 grid. Tune & load
>> caps
>> have no effect on grid or plate current while trying to load. Inline
>> output
>> meter shows no watts out. Wouldn't I see some power out, even if the tank
>> wasn't
>> right ? Thanks to all in group that can help. ku4uk
Rich, AG6K, 805-386-3734, www.vcnet.com/measures
|