Topband: How Increase 160m power on FL2100z

[Tom W8JI]

A proper tank would be about 300-330 pF on the tune side (allowing for plate 
choke reactance) and 2000 pF on the load. This requires 33 uH on the total 
inductance.

Yaesu has way too little tank inductance and that causes the capacitance to 
be excessive. This puts the Q up in the 20 range, which is not necessary.

It is possible it has an open load padding capacitor, because they are 
notorious for going open, but the real fix is to correct the tank by 
increasing inductance (which reduces loaded Q) so it "acts normal".


73 Tom

----- Original Message ----- 
From: "JC N4IS" <n4is at comcast.net>
To: <topband at contesting.com>
Sent: Sunday, April 20, 2014 10:57 AM
Subject: Re: Topband: How Increase 160m power on FL2100z


>I owned a FT2100Z for several years and the power on 160m was the same as
> other bands. I don't expect any design flaw. The original tubes are not
> available anymore, the  572's tubes manufactures nowadays are different 
> and
> optimized for audio applications and does not perform at the same level as
> the originals 572's. You may just need more drive or change the input
> circuit for 160m.
>
> Regards
> N4IS
>
>
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