TopBand: z measurements

[W8AV@aol.com]

In a message dated 98-08-06 00:01:07 EDT, you write:

<< Does anyone know if this bridge will work on 160m, and/or if GR made
another
 model for hf?  I thought about making my own bridge since I have an estimate
 of what impedances are involved, but suspect that would be one too many
 projects for this summer.  Any ideas of info?  73 Bob W7LR in Montana. Not as
 hot as Texas but still about 95 daytime.  
  >>

I don't know much abolut the GR-1603A bridge but would assume from what you
posted that it might not work.  I will research it though.  As for another GR
bridge that will work on 160 try the GR-1606A.  I have one here that I use to
measure the impedances on my 160 vertical and it works fine.  Or, if you can
find a broadcast station that has a Delta OIB-1 or OIB-3 that you can borow,
that would work very well too.

A word of caution , though.  Do not put more than about a watt or two into the
input side of a GR-1606 bridge from the signal source.  If you do you will fry
the small current limiting resistor in the input of the bridge (learned that
one the hard way).  I use my MFJ -259 as the signal source and either a rig or
a commercial Potomac FIM field strength meter for the detector.  The
arrangement works fine.  If you use the OIB you can put up to 5 kW into it if
need be with no adverse effects (although 100w will be more than enuf).

Hope that this helps.

73...................de Goose W8AV

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