>I need a little help in understanding the entire picture correctly.
>
>I see that having additional bypass C at the plate choke base, would help
>prevent the power supply from becoming part of the tuned circuit.
** The rub is that power supply components don't do well with RF. The
antenna is probably a better place to put RF.
>Would
>additional L of the choke also be beneficial, as it would seem that less RF
>current would be lost through the bypass C at the choke base?
** Current is not lost in a C or an L because only the voltage/current
phase relationship changes. Additional L is beneficial in that it
reduces the level of RF in the HV-PS, however, the tradeoff is increased
chance of a HV-RFC choke fire on some operating freq. Amplifier
engineering is a balancing act.
>Or, is that
>current insignificant? Or am I missing the entire plot?
>
** I try to keep the AC max choke current at the lowest operating freq.
under 50% of I-anode (DC) This holds the HV bypass C current to
something that ordinary disc ceramic caps can handle, and it holds I^2 x
R loss in the choke wire to something semi-reasonable.
>
have phun, Jeff
>
>----- Original Message -----
>From: "2" <2@vc.net>
>To: "Phil Clements" <philk5pc@tyler.net>; "Lynn" <no9z@soltec.net>; "AMPS"
><amps@contesting.com>
>Sent: Thursday, May 29, 2003 9:54 AM
>Subject: Re: [Amps] Re: 160M efficiency
>
>
>> >> Yesterday I added 1600pf (4 doorknobs) to the base of the plate
>> >> choke and noticed a
>> >> significant change in output as well as stability. It seems the
>larger
>> >> metal tubes
>> >> require more bypassing than found in some of the other designs.
>> >
>> >
>> >All 160 meter amps need this, Lynn. It is just not as obvious at low
>power.
>> >You need 8000-10000 pf at the base of the plate choke for 160, especially
>> >if you
>> >are using a string of electrolytic capacitors in the HVPS. I use 10,000pf
>> >@ 10kv
>> >disk ceramics by Sprague here.
>>
>> ? Amen, Phil. Ameritron's 1000pF of +HV bypass C is clearly not good
>engineering practice below 10MHz..
>>
>> >
>> >(((73)))
>> >Phil, K5PC
>> >
>> >
>> >
>> >_______________________________________________
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>> >Amps@contesting.com
>> >http://lists.contesting.com/mailman/listinfo/amps
>>
>>
>> Rich, AG6K, 805-386-3734, www.vcnet.com/measures
>>
>>
>> _______________________________________________
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>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>>
>
>
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