[AMPS] HV choke

[measures]

>
>> Anyone out there with an idea of an optimum HV choke, in order to avoid
>resonances, for the following conditions:
>>
>> Plate impedance = 2500 ohms
>> HV = 5kV
>> freq = 1.8 - 30 MHz
>>
>> Inductance ? Winding ? Sections ? Physical size ?
>>
>> Best 73s de Lars / SM3BDZ
>
>I assume you are requiring continuous coverage 1.8-30 mhz
>with no resonances anywhere. The way Henry, Alpha, and
>Creative Electronics do this is with two chokes and a relay.
>The Henry 8-K Ultra, which is close to the operating perameters
>you listed uses a 19uh and a 184 uh  choke mounted at right angles
>to each other. The big choke is shorted out with a relay  above 20 meters.
>The others use similar schemes; Creative does not short the big choke.
>They pull two parallel 4700pf 6kv disk ceramic caps to ground that
>are attached at the connection between the two chokes. I like that
>idea because it removes the D.C. from the relay contacts.
>
>With 9  ham bands, let alone continuous coverage, it is almost
>impossible to find a place to "park" the resonance using only one
>choke.

....in the Ugly amp., the large choke's resonance is parked on 15MHz WWV. 
 
>
>I purchase my chokes and relays from Henry and Creative. 

Winding your own chokes saves big bucks.  


-  Rich..., 805.386.3734, www.vcnet.com/measures.  


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