[Meteor-Scatter] 2 x 17b2's

Fri, 23 Aug 2002 08:16:26 -0400

Rick, the little transformers like that on my KLM 16LBX's get very hot when
fed with legal limit. So far they seem to still work ok though.  Perhaps one
of yours could be damaged by excessive heat or by moisture getting into the
coax.  I'd suggest removing the baluns and connecting them to a suitable
resistive load and then see if they measure differently.  You could also
switch baluns between the two antennas and in that way see if the difference
is in the balun or the antenna.

GL, Russ K2TXB

> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of Rick Muller
> Sent: Friday, August 23, 2002 8:00 AM
> To: [email protected]
> Subject: [Meteor-Scatter] 2 x 17b2's
>
>
> sorry for bandwith , not a real METEOR related issue ..but I expect a
> lot of Hams to be on this reflector ...maybe one of you has seen same
> issue ...
>
>
>
>
> busy here with stacking 2 x 17b2 ( cushcraft)
>
> I borrowed a MFJ 259B analyse tool  from a friendly ham to make sure
> that I got the correct cable lenghts to make ...
> Well turned out that I have to get more cable
>
> but I used the same insrument to "inspect" the two dipoles of the 17B2,
>
> I used only a segtion of 4 elements of a 17b2 ( dipole + 3 elements)
> beacuse I have two antenna's I could easely exchange the dipole
>
> surprise ...I get complete different readings from the MFJ tool using
> same antenna , same hight
> same coax cable ( but different dipoles )
>
> I checked the physical dimensions of the dipoles but there are no
> differnces there .
> Cuschraft is using a 1:4 coax transformer inside the little plastic box
> + ferrite ring.
> The coax is quite thin ( RG 58 style ) I can not find a type on the coax
> ( on the old style boomer they used a real 1/2 wave coax cable ..)
>
> has anybody ever seen these 17B2 1:4 transformers go " bad" ???
>
> I was quite surprise to see the differences in the dipoles using the MFJ
> tool
>
>
> 73's Rick ( PA1BVM ) in JO21
> _______________________________________________
> Meteor-Scatter mailing list
> [email protected]
> http://mailman.qth.net/mailman/listinfo/meteor-scatter
>