[Amps] 200-ohm tank and "un-un" in HF amp design?

[Jim Barber]

1500 watts
4kV, 625mA
Single 8877 at around 4000 ohms plate impedance in AB2.

Tnx,
Jim N7CXI


Sent from mobile wireless



-------- Original message --------
From: Jim W7RY <w7ry at centurytel.net> 
Date: 10/20/2013  6:31 AM  (GMT-08:00) 
To: amps at contesting.com 
Subject: Re: [Amps] 200-ohm tank and "un-un" in HF amp design? 
 
What kind of power?  What plate voltage and current on the tube?

73
Jim W7RY


On 10/20/2013 12:51 AM, Jim Barber wrote:
> Assuming adequate core/wire sizing and airflow, can anyone think of a 
> solid reason *not* to design a legal-limit HF amp output tank for 200 
> ohms, then use a 4:1 "un-un" transformer to step it down to 50?
>
> I'm curious because doing so would bring the loading cap requirement 
> for a 4000-ohm plate impedance down to under 1000pF at 1.8 mHz, which 
> can be done with a large air variable alone.
>
> Note: Yes, I know it *has* been done already, but I'm asking for 
> opinions as to whether you think it should be.
>
> Thanks and 73,
> Jim N7CXI
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>

_______________________________________________
Amps mailing list
Amps at contesting.com
http://lists.contesting.com/mailman/listinfo/amps