Hello Folks...
> Ken, UA9FGR, had one of the ferrite beads fail in the MN-7 matching
network
> for a R7 vertical. Can these beads be replaced or does he need a new MN-7
> matching network?? Has anyone replaced these beads, if so with what type
> of ferrite core material did you use. I need to help Ken get his antenna
> working again.
>
> Thanks-N2AU
As I remember, the ferrite cores in the R7 used Q1 material with a
permeability of about 125. The circuitry is pretty basic and easy to figure
out ....There are two cores (both the same)... The first is wound with RG58
coax as a choke balun to isolate the coax, and the second is ( as far as I
can figure) a 4:1 voltage balun...Centre tap is fed, one output leg to the
radials, and the second to the vertical via a series capacitor of approx
45pF..(two 86pF in series I think)
The ferrite cores are quite large...over 2ins OD.
I hope this helps..
73
de
John EI7BA http://www.iol.ie/~bravo/
List Sponsor: Champion Radio Products - We'll be at the Dayton Hamvention
with all of our safety equipment and other products. Stop by booth #559 and
say hi.
<A HREF="http://www.championradio.com";>www.ChampionRadio.com</A>
-----
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|