Hi Ed,
I think Tom is using the Ameritron RB-704, which has a keying relay and
isolates the amp from the radio. I think the rig keys the buffer and
the buffer keys the amp and prevents any possible damage to the keying
circuit in the radio.
Here are 2 places to look for ferrites:
https://www.amidoncorp.com/
http://www.allelectronics.com/make-a-store/category/235/Ferrites/1.html
A few years ago I loaded up at All Electronics when the snap on beads
were $1.25 each, or 10 for 10$. Prices have gone up since then. The
stock at All Electronics varies over time and a lot of times the mix of
the ferrite is unknown. If you need a particular mix for a particular
application, look at Amidon.
73, Steve KW3A
On 4/9/2011 9:50 AM, Ed Malmgren wrote:
> I guess I'm a bit slow but what is the buffer in tom's lash up for? and also
> Steve where is a good source for a variety of different sizes of ferrites?
> I haven't used those very often. Thanks, 73
> Ed K7UC
> ----- Original Message -----
> From: "Steve Forst"<[log in to unmask]>
> To:<[log in to unmask]>
> Sent: Saturday, April 09, 2011 6:21 AM
> Subject: Re: looks like it's back to the head scratching on my 20-meter RFI
> Problem
>
>
>> 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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