[Elecraft] K3 - why SWR change with an amplifier

[Jorge Diez - CX6VM]

I just tested with the 89 and also have different readings.

With the antenna directly into the K3, SWR is 1.5:1

When both amps are in stby, SWR is 1.5:1

Will do some measurements on different bands and will let you know

73,
Jorge


-----Mensaje original-----
De: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] En nombre de W0MU Mike Fatchett
Enviado el: Jueves, 29 de Marzo de 2012 09:39 p.m.
Para: elecraft at mailman.qth.net
Asunto: Re: [Elecraft] K3 - why SWR change with an amplifier

He says it is happening with an Alpha 89 too.  Something is not right.

What happens when you hook the antenna directly into the K3?

Mike W0MU

W0MU-1 CC Cluster w0mu.net


On 3/29/2012 6:34 PM, Don Wilhelm wrote:
> Jorge,
>
> If the K3 does not fault and reduce power, it may be OK - SWR = 2:1 is 
> the "trip point" for the KPA3 power reduction.
> Do check all bands, it could be better (or worse) on some bands as 
> opposed to others.
>
> 73,
> Don W3FPR
>
> On 3/29/2012 8:22 PM, Jorge Diez CX6VM wrote:
>> Don
>>
>> The amplifier is a Drake L7
>>
>> I will test with a ALS1300 to see what happens
>>
>> So what do you think? My L7 is doing something bad?
>>
>> I really dont like to see more than 3 bars in my K3 SWR meter. I tune 
>> with the internal tuner and is better, but I dont know if I had 
>> something bad that I need to solve
>>
>> Thanks
>> Jorge
>>
>>
>> Enviado desde mi BlackBerry® device de Antel
>>
>> -----Original Message-----
>> From: Don Wilhelm<w3fpr at embarqmail.com>
>> Sender: elecraft-bounces at mailman.qth.net
>> Date: Thu, 29 Mar 2012 19:39:03
>> To: ab2tc<ab2tc at arrl.net>
>> Reply-To: don at w3fpr.com
>> Cc:<elecraft at mailman.qth.net>
>> Subject: Re: [Elecraft] K3 - why SWR change with an amplifier
>>
>> He did not say it was a KPA500!  Maybe it was some other amplifier 
>> that we cannot comment on.
>> If it were the KPA500, I would have asked "what bands".
>>
>> 73,
>> Don W3FPR.
>>
>> On 3/29/2012 7:26 PM, ab2tc wrote:
>>> Hi,
>>>
>>> But is it normal for the KPA500 input SWR to be 2:1?
>>>
>>> Knut - AB2TC
>>>
>>>
>>> Don Wilhelm-4 wrote
>>>> Jorge,
>>>>
>>>> With the amplifier in standby, the K3 wattmeter sees the antenna 
>>>> SWR - the same as when the antenna is connected to the K3.
>>>> When the amp is switched to operate, the K3 will see the input SWR 
>>>> of the amplifier - and that has no relationship with the antenna.
>>>>
>>>> 73,
>>>> Don W3FPR
>>>>
>>>> <snip>
>>>>
>>> --
>>> View this message in context: 
>>> http://elecraft.365791.n2.nabble.com/K3-why-SWR-change-with-an-ampli
>>> fier-tp7419653p7419681.html Sent from the Elecraft mailing list 
>>> archive at Nabble.com.
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