OT: FL-2100Z input SWR

[DaveVK]

Hi folks,

I have decided to try you guys on this reflector for help as a last DIY
resort.

I have an FL-2100Z and it has relatively high SWR on 80, 40, and 20
meter bands of around 1.9 to 2.0.  Does anyone having insight in how to
adjust this?

Regards,

Dave
VK2NA
K2/100 SN: 3222
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[Don Wilhelm-4]

Dave,

That amp has a tuned input circuit.  It may need some tuning or re-design.
The FL-2100 was designed to be 'good enough' to be driven with the
vacuum tube exciters of similar vintage.  Most of those exciters could
be tuned to tolerate a 3:1 or even greater SWR, so there was no need to
design the amp input circuit to be close to 50 ohms resistive.  As a
result, some re-design or tweaking of the input components should make
it usable with solid state transceivers.

73,
Don W3FPR

David Walker wrote:
> Hi folks,
>
> I have decided to try you guys on this reflector for help as a last
> DIY resort.
>
> I have an FL-2100Z and it has relatively high SWR on 80, 40, and 20
> meter bands of around 1.9 to 2.0.  Does anyone having insight in how
> to adjust this?
>  
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[Arie Kleingeld PA3A]

David,

I had a fl2100z for years and just sold it a few weeks ago to make room
for a K3.

As Don said, the input is fixed but there is another thing that gives
you the higher SWR: feedback form the tuned anode circuit. There is a
neutrodynisation capacitor for that. It is supposed to neutralize the
feedback.
In your case, you'll probably see the SWR going up and down when you
tune the Amp. The capacitor is not properly set then.

The neutralizing capacitor must be set that there is little change in
SWR when you tune.


For the rest: use the auto tune of the transceiver. Done that for years
and worked fb.

73 Arie PA3A



-----Oorspronkelijk bericht-----
Van: [hidden email]
[mailto:[hidden email]] Namens David Walker
Verzonden: zaterdag 10 mei 2008 15:03
Aan: [hidden email]
Onderwerp: [Elecraft] OT: FL-2100Z input SWR


Hi folks,

I have decided to try you guys on this reflector for help as a last DIY
resort.

I have an FL-2100Z and it has relatively high SWR on 80, 40, and 20
meter bands of around 1.9 to 2.0.  Does anyone having insight in how to
adjust this?

Regards,

Dave
VK2NA
K2/100 SN: 3222
_______________________________________________
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Post to: [hidden email]
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[Jim Wiley-2]

Push the "automatic tune" button on the antenna coupler part of your
transceiver - or whatever you have that performs that function.  It will
match your exciter to the amplifier in a jiffy.  Much easier than
fiddling around with amplifier adjustments.


- Jim, KL7CC



David Walker wrote:

> Hi folks,
>
> I have decided to try you guys on this reflector for help as a last
> DIY resort.
>
> I have an FL-2100Z and it has relatively high SWR on 80, 40, and 20
> meter bands of around 1.9 to 2.0.  Does anyone having insight in how
> to adjust this?
>
> Regards,
>
> Dave
> VK2NA
> K2/100 SN: 3222
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft   
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>
>

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