Tom,
I agree. You can get a cable on ebay for about 20 bucks. I'd be
surprised if the rig buffer is your problem, but stranger things have
happened. You could always add ferrites to the RCA cables between the
buffer and amp.
If it were me, I'd run the full set up, as is, on the second antenna and
see if there is the same problem. If you isolate it to the DXCC, you
are half way home. This would be a good time to have a dummy load that
will handle full power from your amp, to see what happens when the
antennas are out of the equation.
BTW, a few months ago, you had mentioned an interest in adding a LDG
break out box to your wish list. If you have one in the shack, use
the supplied 8 pin din from the 480 to the box, then RCA cables to the
amp. This way you get the buffer out of the system without spending
money on a cable you may not need once you find the real problem.
73, Steve KW3A
On 4/8/2011 10:56 PM, John Miller wrote:
> You can get cables on eBay or I think amaratron now has them, where you can
> connect the radio directly to the amp and you don't need any boxes or
> anything, probably cheaper on ebay and might be worth a shot.
> ----- Original Message -----
> From: "tom behler"<[log in to unmask]>
> To:<[log in to unmask]>
> Sent: Friday, April 08, 2011 9:40 PM
> Subject: looks like it's back to the head scratching on my 20-meter RFI
> Problem
>
>
>> Hi, all.
>>
>> Well, Bob Heil checked out my Heil GM5 mic, Kenwood interface cable, and
>> FS2
>> foot switch in his lab with his TS480 and amplifier, and couldn't
>> replicate
>> my 20-meter RFI problem.
>>
>> So, it looks like it's back to the drawing board for me.
>>
>> You may recall that I had the original RFI problem when using my Alpha
>> Delta
>> DXCC antenna, and when using the FS2 foot switch, so, I think something is
>> creating an RF ground loop somewhere.
>>
>> You also may remember that if I plug the amplifier cable on the foot
>> switch
>> directly into the amplifier relay jack, it partially keys the amplifier,
>> even without my pressing the foot switch.
>>
>> I am considering four things to try when I get back home from Missouri:
>>
>> 1. Trying the original set-up on my Carolina Windom 160 Compact, since
>> that
>> antenna was not working when I initially experienced the problem.
>>
>> 2. Taking the ARB704 buffer box completely out of the circuit, although
>> I'm
>> not sure how I'm going to directly hook up my Ameritron AL811H amplifier
>> to
>> the remote jack on the TS480. The remote interface cable I now have has
>> two
>> mini-din plugs, while there is no jack to accommodate such a plug on my
>> Ameritron amp.
>>
>> 3. Purchasing and installing the 1 to 1 line isolator balun from the wire
>> man that Kevin suggests, at least for the Alpha Delta DXCC antenna; and
>>
>> 4. Making a 20-meter counterpoise wire like some suggest, with one end
>> connected in the shack, and the other hanging out the shack window.
>> Regarding that counterpoise wire, should it be 15 or 16 feet long, and
>> where
>> do I connect the shack end?--to the ground lug on the TS480, or to the
>> common ground lug on my MFJ window feed through panel?
>>
>> If anyone has comments on any of these four strategies, or if anyone has
>> any
>> other suggestions of things to try, please let me know.
>>
>> Thanks, and 73 from Tom Behler: KB8TYJ
>
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