I opened up my TB6EM Balun and it was a simple coax balun on a mat of fiberglass
insulation with a gimmic coil for 10m. It was prefect inside after more than
30yrs.
Have Fun,
dave
wa3gin
"Jim White, K4OJ" wrote:
> I once opened up a telrex box balun to find it full of sand - or something
> akin to it....was very distressed!
>
> I may be able to help you with a lead on some parts for the TB6EM...let me
> know what you need if any.
>
> 73,
>
> Jim, K4OJ
>
> ----- Original Message -----
> From: "Rush Johnson" <RushJohnson@carolina.rr.com>
> To: <towertalk@contesting.com>
> Cc: <w4qa@arrl.net>
> Sent: Thursday, March 14, 2002 5:12 AM
> Subject: [Towertalk] Telrex TB6EM
>
> > Before I climb the tower and start taking things apart, I would appreciate
> > any thoughts from those who have had prior experience with SWR changes on
> > the Telrex TB6EM. I have had this particular tribander installed at the
> > 100' level for about 5 years now with no problems until this past week.
> We
> > have had a good bit of rain recently -- so weatherproofing of connections
> is
> > the first thing I may check.
> >
> > 15 meters seems to be somewhat OK, but the SWR on 10 and 20 meters seems
> to
> > be out of line. On the low end of 10 meters (CW portion 28.025) -- the
> SWR
> > is over 3:1 -- dropping to under 1.5:1 at around 28.600 mHz. The SWR on
> 20
> > Meters is about 3:1 at 14.000 mHz dropping only to 1.6:1 at 14.300 MHz.
> The
> > SWR is not lower than this on 10 and 20 -- 15 meters seems to be ok (1.1 :
> > 1) on the low end -- rising to 2.8:1 at 21.200 mHz.
> >
> > Unfortunately, I can't find the original SWR curves when the antenna was
> > installed -- and the auto-tuner may have been masking this issue for a
> while
> > now. However, it seems to me that I was experiencing less than 2:1 across
> > all the bands when the antenna was first up. I recall the antenna being
> > relatively broadbanded -- but used the auto-tuner in the 761 as a matter
> of
> > course.
> >
> > Of course, this could be: a) normal for the TB6EM, b) a feedline problem,
> c)
> > a balun problem, d) a trap problem -- etc. But, before I start tinkering,
> I
> > thought I would get some advice from those out there that either have a
> TB6
> > or have worked on them in the past. Also -- those that have not had a TB6
> > but something similar -- maybe you can give me some troubleshooting
> > guidance.
> >
> > Related to this -- I am wondering if the Balun that Telrex supplied with
> > this antenna is a 1:1 balun or not? I would like to replace it with
> another
> > one sometimes in the future as a matter of maintenance anyway, but I don't
> > know what characteristics the balun currently has.
> >
> > Thanks in advance for any advice!
> >
> > 73,
> > Rush -- W4QA
> >
> >
> > --- StripMime Report -- processed MIME parts ---
> > multipart/alternative
> > text/plain (text body -- kept)
> > text/html
> > ---
> > _______________________________________________
> > Towertalk mailing list
> > Towertalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
> _______________________________________________
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> Towertalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
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