[MRCA] M and S net - being more careful

[W2HX]

A coupla weeks ago I checked into the M&S Net with my newly acquired racal
BCC-39B. I have an antenna over the house so I decided to bypass the built
in ATU which has only a whip attachment and limits output to 25W.  By
passing would allow me to run 50W and have a bnc connector.  Despite my OCF
dipole having a terrible match on 60m and with an SWR of 3:1 I was able to
get a signal out and had some nice sig reports.

Talking to another owner of this radio, I remembered that this radio puts
out 24VDC on the antenna BNC connector. This is used to power the ATU and by
sending PWM on that 24V antenna BNC connector, it can send band information
to the ATU (very clever). This allows the ATU to be situated 50 meters away
from the radio itself if necessary using only an RF cable and no other
control cable. 

At some point a few days after my check into the net, it struck me that my
OCF dipole has a balun within it, and might present a DC short to the
feedline.  Well, it does (confirmed by the mfg of the antenna). So I started
getting a worried that a) I might have damaged something in the radio by
presenting a short or b) damaged the balun putting 24VDC across it for about
1 hour (the power is applied in Rx and Tx).   A regular dipole without any
dc path between the segments would of course, be fine.

I am still doing the circuit analysis to see what could have actually
happened, but suffice it to say, I need to be more thoughtful when
connecting seemingly innocuous radio system components. And a reminder to
other folks as well. Think twice, connect once! I'll report back if anything
actually did get damaged (btw: I am pretty sure the radio wont be damaged
but I'll have to double check).  

 
73 Eugene W2HX