Topband: Front End Savers- summary

[W5FKX - Don]

Thanks to all (14!) who responded to my 160m newbie request for info
regarding the need for front end savers (FES) when using a separate Rx
antenna connected to the Rx antenna jack on the FT1000MP or IC756ProII . In
addition to learning a few things about FES, I can also say that this has
been one of the nicest responses (all 100% helpful) that I have ever gotten
on any list. Here is a summary of the results:

-- For usual installations where Tx/Rx antennas have some separation and
operation is barefoot/lowpower on Tx, it is probably not necessary to use a
FES for the FT1Kmp, but it all depends upon power levels.

--The '756P2 apparently does not ground the antenna on Rx (cited evidence
was added 'grass' displayed on the Tx waveform w/Rx antenna; this was
eliminated by use of FES gnd relay).

-- For high-power TX and/or close-spaced Tx/Rx antennas, the majority were
in favor of the added protection afforded by a FES that disconnects and
grounds the Rx antenna during Tx.

-- For those who may forget to disconnect the Rx antenna (despite
disconnecting the Tx antenna), a FES may save you from damage due to static
buildup.

-- RF feedthrough/feedback when running high power may induce it to go into
oscillatation (causing fluctuatations in amplifier power output or drawing
high plate current) and damage the amp.

-- Info on building a FES is available on VE3NH's website:
www.isp.ca/ve3nh/prot.htm

-- FES are available from: KD9SV (see also his article in CQ, Feb. 1997, p.
32-33), or see the Radio-Ware webpage at www.radio-ware.com

My conclusion? Since I run high power on Tx and my Rx antenna will be less
than 30 ft from the Tx antenna, I am going to use a FES with the two rigs.
Oh, BTW, I learned something else: now, I have to begin to plan to ground or
de-tune the Tx antenna during Rx to avoid noise re-radiated from the Tx
antenna!

73,
Don W5FKX
Delta DX Association
http://www.qsl.net/ddxa