Tom,
You need to understand about internal antenna tuners and why I don't
personally use one. They will match only what the rig itself sees. It
won't do anything for your amplifier because the antenna tuner is located in
your rig, between the finals and the antenna feed line. The amplifier, of
course comes after this point.
If you use an external antenna tuner, the block diagram representation would
be the output of your transmitter/transceiver going to the input of your
amplifier; the output of your amplifier going to the input of your external
antenna tuner, and the output of your tuner feeds the antenna. Therefore,
when you tune the tuner for a 1:1 SWR, everything before it also sees the
one to one SWR.
Now, using a tube amplifier, it probably won't get as upset about seeing a
larger mismatch as a solidstate transceiver would. However, when you tune
your transceiver with the internal tuner to the antenna, and then insert
your amplifier, you are likely trying to feed the amplifier with a
mismatched impedence. The amp is designed to accept a 50-ohm signal.
Steve, K8SP
----- Original Message -----
From: "Tom Behler" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, September 28, 2011 10:18 PM
Subject: Re: Strange Power Readings With LDG TW1
> Bob:
>
> But what about running the Ameritron al811H?
>
> Would I be setting myself up for trouble there, or should I consider
> myself
> to be ok if the Tentech 238A manual tuner tunes it down to a 1 to 1 SWR
> when
> I use the amp?
>
> I just don't want to risk damaging anything.
>
> 73 from Tom Behler: KB8TYJ
>
> ----- Original Message -----
> From: "Bob Tinney" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Wednesday, September 28, 2011 10:02 PM
> Subject: Re: Strange Power Readings With LDG TW1
>
>
>> Tom,
>>
>> IF your internal tuner will tune it, go for it. If you have another
>> external tuner, try that.
>>
>> Good Luck!
>>
>>
>>
>> Bob Tinney, K8LR, [log in to unmask]
>> Skype, bobtinn
>> We could certainly slow the aging process down if it had to work its way
>> through Congress!
>>
>> ----- Original Message -----
>> From: "John Miller" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Wednesday, September 28, 2011 8:45 PM
>> Subject: Re: Strange Power Readings With LDG TW1
>>
>>
>> If the tuner tunes it, I'd run it, if there's a mismatch, the radio will
>> role back and most likely, you'll know it.
>> ----- Original Message -----
>> From: "Tom Behler" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Wednesday, September 28, 2011 8:27 PM
>> Subject: Strange Power Readings With LDG TW1
>>
>>
>>> Hi, folks.
>>>
>>> Maybe I ought to go back to basic antennas 101 class, but I just found
>>> out
>>> something with my Carolina Windom 160 compact that doesn't quite make
>>> sense
>>> to me.
>>>
>>> I am testing out the antenna to see if water got back into it after the
>>> week
>>> of rain we have had here, and I discovered some strange power readings
>>> with
>>> my LDG TW1 talking watt meter.
>>>
>>> Right now, my Carolina Windom, such as it is, seems to be resonant on
>>> the
>>> lower end of 80 meters--right around 3.600 MHZ.
>>>
>>> As expected, then, when I go to the upper phone part of the band, say
>>> around
>>> 3.976 MHZ, my sWR rises dramatically to a blistering 6.0 to 1.
>>> (ouch!!!!!!)
>>>
>>>
>>> Interestingly, though, the auto tuner in the TS590 tunes the antenna,
>>> which
>>> was a bit of a surprise to me.
>>>
>>> I then took some forward and reflected power readings with my TW1, and
>>> was
>>> told that the forward power was 102 watts, while my reflected power was
>>> 52
>>> watts.
>>>
>>> Again, this is with the auto-tuner engaged.
>>>
>>> Can someone tell me what is going on here?
>>>
>>> To be honest, I'm still a bit hesitant to use the Carolina Windom, given
>>> the
>>> water problems I have had of late.
>>>
>>> Would this antenna be safe to use on the top part of 80 meters, since
>>> the
>>> auto-tuner clearly tunes it, or am I just kidding myself here.
>>>
>>> And, could I safely use this antenna on the upper part of 75 meters with
>>> my
>>> Tentech 238A manual tuner and Ameritron
>>> AL811H amplifier?
>>>
>>> I guess I'm now a bit gun shy.
>>>
>>> 73 from Tom Behler: KB8TYJ
>>
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