Re: [Amps] Alpha Input SWR

["Hardy Landskov" <n7rt@cox.net>]

My K3 has a real problem driving the 8410. Even with the matching network it 
has a problem I can't seem to understand.
The SWR on 12 m is over 3:1.
Hardy N7RT

----- Original Message ----- 
From: "Peter Voelpel" <dj7ww@t-online.de>
To: <amps@contesting.com>
Sent: Friday, January 09, 2015 7:26 PM
Subject: Re: [Amps] Alpha Input SWR


> What is bad about SWR <2?
>
> 73
> Peter
>
> -----Original Message-----
> From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Hardy 
> Landskov
> Sent: Samstag, 10. Januar 2015 03:09
> To: Charles Henry; ed@w0yk.com; amps@contesting.com
> Subject: Re: [Amps] Alpha Input SWR
>
> Charly,
> Changing the length of coax to the input will not change the SWR. Look at 
> a
> Smith Chart.  Only dealing with the tube's capacitance along with the 50 
> ohm
> resistor to ground with a suitable matching network will lower the input
> SWR. I wish Alpha and whoever is the designer of amps now would  match the
> input to every band but they don't. It's not that much more money to do it
> right.
> I am going to sell this 8410 because of that reason. What a piece of junk.
> 73 HNY to all....  Hardy N7RT
>
> ----- Original Message ----- 
> From: "Charles Henry" <k4vud@hotmail.com>
> To: <ed@w0yk.com>; <amps@contesting.com>
> Sent: Friday, January 09, 2015 3:15 PM
> Subject: Re: [Amps] Alpha Input SWR
>
>
> > All I have been able to do is to cut and try the length of the drive coax
> > from the radio RF output to the amplifier input.
> > Sri forgot the lengths and never got 1:1 anyway.   Charly
> >
> > > From: ed@w0yk.com
> > > To: amps@contesting.com
> > > Date: Fri, 9 Jan 2015 08:44:18 -0800
> > > Subject: [Amps] Alpha Input SWR
> > >
> > > What experience can anyone share for reducing the input SWR on Alpha
> > > amps?
> > > On some bands the input SWR is 1.6:1 or higher on our 86A, 87A and 91B
> > > amps.
> > >
> > > Thanks,
> > > Ed W0YK
> > >
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