[TenTec] Eagle problem?

[Bob McGraw - K4TAX]

Agreed, that is a tough RF environment.  The use of a common mode choke on 
the feedline, be sure every piece of equipment is securely bonded to a 
common point, making sure all PL-259's are very tight not just finger tight, 
and us good quality coax {high % of shield} is about the best one can hope 
for.

Although I understand from our earlier discussions, space and position for 
antenna's at your QTH is an issue.  Thus more separation between antennas 
and radios is desireable to help your issue.  Just may not be possible.  Not 
recalling your antenna configuration, perhaps changing antenna length will 
change the voltage point issue relating to 30M.  This of course might make 
other bands difficult to match.

73
Bob, K4TAX










----- Original Message ----- 
From: "Brian Carling" <bcarling at cfl.rr.com>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Saturday, May 24, 2014 1:37 PM
Subject: Re: [TenTec] Eagle problem?


>I got problems with RF in the shack getting into equipment on 30 m. However 
>the inverted V I am using his right outside the window on one end and only 
>about 8 feet from the equipment. So I can hardly complain. In such cases 
>most of the remedies described here involving RF chokes etc. on the 
>feedline and other measures inside the shack will not make much difference. 
>It's just a case of too much RF too close by.
>
> Best regards - Bry Carling
>
>
>
>> On May 14, 2014, at 5:56 PM, Stuart Rohre <rohre at arlut.utexas.edu> wrote:
>>
>> Some Yaecomwoods do suffer from RF entering the rig.
>>
>> MOST ANY rig will if you have a bad shield connection on coax jumper, or 
>> have rig too close to the antenna, (second floor shack), and there are 
>> many other rig and feedline issues to rule out in any RFI case.
>>
>> Rule of thumb:  Power all equipment from same circuit breaker of the 
>> house.  That ensures AC grounds will not be coming from widely different 
>> locations.  IF you have to use a long ground wire for lightning 
>> protection ground on the station (like from second floor shack), consider 
>> that it could act as an "antenna" for pick up of RF from the real 
>> antenna. You may need tuned radials, or a radial for each favorite band.
>>
>> You could always examine the quality of the grounding of the mike cable 
>> shield.  Some older mike cords had just a multi-strand wire wrapped in 
>> one direction and not a hatch pattern wire shield.  Some aluminum foil 
>> shields don't make a good low impedance connection by clamping. 
>> (Connections that can't be soldered are suspect).
>>
>> You can do a step by step analysis of grounding, by starting at the mike 
>> element and measure the resistance by ohm meter, of shield connection to 
>> plug pin/ shell.  Use a magnifier to examine connections on inside of 
>> radio at mike.  Check case to mike jack shell if that type.
>>
>> Some radios have a thru bolt to provide a "ground" terminal on back of 
>> set.  Make sure this bolt if present, grounds tightly to the chassis.
>>
>> Same could be said for any stud grounds on external tuner, etc.
>>
>> Good Luck, but usually a step by step exam of all connection points will 
>> show up issues.  Avoid feedlines that are odd multiples of a quarter 
>> wavelength.  Add 5 feet to a line to check for those types of issues.
>>
>> It used to be a common problem if the ring on mike connectors was not 
>> fully tight on the mike jack. That is less of a problem, if the mike 
>> ground carries through a mike pin.
>>
>> Let us know what you do to fix the problem.
>>
>> Stuart Rohre
>> K5KVH
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