[Boatanchors] Station Set up follow up questions

[K0DAN]

Not familiar with the CE100V but if it has a "spot" switch, you activate 
that and it puts out a little RF without triggering the relay (and muting 
your RX) and you can locally hear enough signal to "spot" your TX and RX to 
zero beat.

Without a spot switch, you have a problem...by keying the TX, even into a 
dummy load, you have muted your receiver! You might see if you can still use 
headphones, perhaps the headphone circuit is not also muted.

When I operate boatanchor gear I use a Dowkey relay, but do NOT mute the 
receiver. Yes, I could get feedback, but I would just manually put the RX in 
standby or ride the RF gain control. I never had a problem doing this tube 
gear, provided the relay always kept the transmitter and receiver separated 
from the antenna.

Since I mostly operat using headphones anyway, I prefer the audio feedback 
through the cans, and am also always sure of being zero beat with the other 
station.

As to the hum I'd suggest moving the relay somewhere non-resonant. Why not 
get a PL259 male "barrel" connector and put it on the output of the 
transmitter? Now the relay is part of the transmitter, and from here you 
connect your antenna and releciver. Chances are, all that iron will not 
conduct the hum the same way your wall is!

GL es 73

Dan
K0DAN


----- Original Message ----- 
From: "Eugene Hertz" <ehertz at tcaf.org>
To: <boatanchors at mailman.qth.net>
Sent: Monday, October 23, 2006 2:11 PM
Subject: [Boatanchors] Station Set up follow up questions


Ok, everyone. Thanks a ton for the suggestions on the TR-change over relay 
situation. I now have my 51J4 and my CE100V all wired up! When I key the 
100V, the antenna relay fires and the J4 mutes! Things are getting very 
exciting now!

So, a few follow up Q's.
1. When the TR Relay (a dow 115vac relay) is in transmit mode (coil 
energized), there is a distinct 60Hz hum coming from it. I am sure it is 
amplified by the wooden board it is mounted on and the wall that the board 
is in turn, mounted on.  I was wondering if I could reduce that hum by 
putting a rectifier in place? I am not sure if I would need a smoothing cap 
or not, but maybe just the rectifier? Can anyone tell me a) if this could 
alleviate the hum b) if it would alleviate the hum but I would need a cap, 
c) if there would be a detrimental effect to the relay by doing this? The 
total Vp-p would be higher is my undertsanding once it is 
rectified/filtered? I was not thinking of using any transformer at all in 
this process (mistake?)

2. Thinking in terms of tuning both Tx and Rx separately, I have always 
heard of the term "talking yourself on frequency." My understanding was 
there is some way to leave the receiver on the frequency you want to use and 
then tuning the transmitter until you hear yourself.  This seems very 
logical to do. But how to do this with the muting/relay stuff? Should I have 
some kind of override switch to prevent the receiver from muting when 
attempting to set the frequency? Would I need any RF connection between the 
Tx and Rx? Otherwise without any explicit rf connection, the Tx would be 
connected to the antenna and the Rx would simply have a length of coax to 
the TR relay but it would be unterminated as the open circuit leg of the TR 
relay. But perhaps that would be enough to get some signal in?

Thanks again in advance!
Eugene





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