Re: Beam Restoration

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From: Stan Goldstein (stan@cruzio.com)
Date: Sat Sep 14 1996 - 13:28:18 EDT


chuck adams wrote:
>
> Gang,
>
> I have and have had in my possession one Telex hy-gain
> Model TH2MK3, 2-element, 10/15/20 meter, trap beam for some
> time.
>
> Secifications
>
> Forward gain ........ 5.5 dB
> Front-to-back ........15-20 dB
> Maximum power input .. 1kw AM (not a worry at this station)
> VSWR (at resonance) .. 1.2:1
>> Gain is not given a reference so I'll assume Isotropic.

Nice lil beam. I've heard and seen that telex makes some good rugged
stuff.

1 kw out ? since you usually only use < 1 watt, I would make sure that
the minimum power needed to drive the beam is that low, when you
calculate wire loss and add in the multi-element losses, you may not
be running enough power to properly drive the beam to realize its
potential over a dipole.

 
> So, will using a plastic scrub brush and scowering pad with
> Aluminum pot household cleaner be sufficient? I don't want to
> harm the environment or my delicate hands used for electronic
> assembly work. I do plan to keep chemicals out of the traps.
> Just blow them out to remove any critters that have taken up
> and made a home in them.

Just do what it takes to get down to shiney metal .
I usually use 00 or 000 steel wool.

Make sure to use conductive grease in all the joints.

> Also, at 20' I'd guess this is a better solution, although not
> the ideal operating position for such a beam, than say a dipole
> or some long wires. Those more experienced in this area might
> wanna let me know what your experiences are in say a field-day
> operating environment.
>

I think it is a big improvement. The 5.5 db ( actually I would say it is
a tad below 3 db over a dipole ) foreward gain helps some, but for your
listening pleasure, the reduced qrm from the undesired directions really
makes a big difference during field day or other harsh environments.

 
> dit dit es tnx
>
> Chuck Adams (K5FO CP-60) 49/49/50 adams@sgi.com
> EMPS Qs=0 STATES=0 DX=0

Stan, N6ULU


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