[Top] [All Lists]

Re: [Amps] SB-220 high input SWR

Subject: Re: [Amps] SB-220 high input SWR
From: Warren Volz <>
Date: Tue, 12 Mar 2019 23:34:02 -0600
List-post: <>
I’ve got a 6ft cable between the exciter and amp, so that part is covered.

I did some additional testing tonight and now believe it’s only slightly out of 
tune for 20. With a good tuner match and careful adjustment of the tune/load I 
see ~1-1.5 across 40m and then 1.3-2.0 across 50m. I assume it should be higher 
at the band edges?

Assuming that looks normal sorry to bug you guys about a problem that was 
apparently user error.

-Warren KD5YPH

> On Mar 11, 2019, at 4:39 PM, Jim <> wrote:
> Make sure you use at least a 6' RG58 (or similar 66% velocity factor) jumper 
> between the amplifier and the radio.
> Report back as to your findings then.
> Thanks
> 73
> Jim W7RY
> On 3/8/2019 6:30 PM, Warren Volz wrote:
>> All,
>> I believe I have an issue with the input SWR on my SB220. It's
>> frequently around 2:1 on 40 and 20m. I believe this is not where it's
>> supposed to be. Is it worth adjusting the input coils or would it be
>> better to check elsewhere for issues? Someone suggested checking the
>> mica caps connected to the band switch. When I rehabbed this amp I
>> thought I checked those and they were ok, but it's possible something
>> changed or I didn't actually confirm they were working.
>> -Warren KD5YPH
>> _______________________________________________
>> Amps mailing list
> _______________________________________________
> Amps mailing list

Amps mailing list
<Prev in Thread] Current Thread [Next in Thread>