Topband: cutting coax stubs for 80 meter 4-square

[terry burge]

Richard,

You are so right about that static issue. I even seem to remember the Rig Experts manual says to short the antenna leads together to remove any static build up before connecting the analyzer. I think that was why I wasn't too impressed with my MFJ-259b. Probably my own fail when I first got it. But I did seem to get some pretty Squirrely results that didn't reassure me that it was a solid performer. Now look how it saved the day. But at least my Rig Experts is back in operation after correcting a poor solder joint on the SO-239 connector.

Terry
KI7m

> On June 10, 2018 at 7:56 PM "Richard (Rick) Karlquist" <richard at karlquist.com> wrote:
> 
> 
> On 6/10/2018 10:27 AM, Jim Thomson wrote:
> 
> > ## Seems to me  MFJ  supplied a HP filter when using the MFJ-259B,  to kill
> > anything <  1.8  mhz.
> > 
> > Jim  VE7RF
> >
> 
> IIRC, what MFJ supplied was a tunable NOTCH filter, which might work OK
> in situations where there is only one station that is strong
> enough to upset the MFJ-259B.  Of course you can't calibrate out
> the filter, so it could degrade measurement accuracy.  Far from a panacea.
> 
> My QTH is 6 miles from a 50 KW station on 1140 kHz.  My 259B
> is useless on 160 meters and marginal on 80 meters.  I vaguely
> remember the 259B getting messed up by a channel 3 TV station
> that is 8 miles from me running 100 KW.  I don't have the MFJ notch filter.
> 
> I recently got a Rig Expert AA-55 and it is unaffected by AM BCB QRM and
> works perfectly on my 160 meter vertical with no help from
> external filtering.  It has many other advantages over the 259B.
> 
> One thing you have to be careful about is to always use a DC
> block between the Rig Expert and the antenna.  (You can calibrate out 
> the DC block).  Otherwise, static DC voltage could blow out the front 
> end.  I'm guessing that that is the likely reason why your Rig Expert 
> failed.
> 
> Rick N6RK
> _________________
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