[CQ-Contest] What RF voltage OK at Rx in SO2R?

[Marijan Miletic, S56A]

1W or 7 V RF at 50 Ohms is a safe bet for RX survival.  You might install
two pairs of back-to-back protection Si diodes to keep RF at 1,5 V which is
also within IMD3 RX capabilities.

Using bandpass filters is highly recommended.  Coax stubs are cheaper
solution due to lower Q.

WRTC-2000 measurements with 100 W TX and tribander showed about 3 V RF on
nearby wideband 40 m long Windom antenna.

73 de Mario, S56A, N1YU with few smoked RX repaired.
www.miletic.net or http://artinian.bit.si/radio.htm


  ----- Original Message -----
  From: Jerry Flanders
  To: cq-contest at contesting.com
  Sent: Sunday, September 23, 2001 2:43 PM
  Subject: [CQ-Contest] What RF voltage OK at Rx in SO2R?



  I am trying to set up for RTTY SO2R and have two questions:

  1. What voltage levels can solid state rigs safely tolerate from nearby
tx?

  2. I read about guys using stubs as well as filters in SO2R. How much of
  this is just to protect the rx hardware, and how much is there to improve
  normal rx on band A while tx on band B is underway?



  I would like to avoid smoke testing the rx front ends on my FT-1000D and
  IC-756PRO if possible. I intend to measure actual voltage present on my
  (well separated) rx antennas while transmitting and determine from that if
  I actually need protection, and to what degree. This is aside from the
  question of rx overload, which I can see for myself once I get it all in
  actual operation. My immediate goal is to see if I can safely tx w/o smoke
  before I start working with stubs or filters.

  Jerry Flanders  W4UK


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>From TG9AJR" <tg9ajr at itelgua.com  Sun Sep 23 23:24:26 2001
From: TG9AJR" <tg9ajr at itelgua.com (TG9AJR)
Date: Sun, 23 Sep 2001 16:24:26 -0600
Subject: [CQ-Contest] Build my station !
Message-ID: <00ce01c1447e$81309f60$9884e6d8 at guest>


Hi all,

Ohh, Is good to be back on the air !!!

I'm having a couple of ideas here and there, I guess Ideas that we all had
or have at some point in our Contest journey and it is to build up my
station, something more competitive from what I currently have at home
(your home).

So I will be honor to hear ideas, comments, suggestions, plans, diagrams
or what ever you can and want to share with me about building something 
from zero, with whatever from a single tower to maybe a couple of them up.

In advance many thanks for those responding, anything will be value to
this project which I hope to put together to make some noise and share it
with all you.

73's DX de,

Juan Carlos Munoz.
TG9AJR
tg9ajr at itelgua.com


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