[R-390] AN/URM-25s

[rbethman]

I also had the prior experience of being on a team performing Patrols in 
the Jungle in SE Asia.  We carried PRC-25s with 1 to 1.5W output, and 
for long haul the PRC-47s.

Were were always aware of the limitations of the radios, and had 
compromises that had to be dealt with.

When you were on the move, the standard measuring tape style whip on the 
PRC-25s, we would grab the top of it, and bend it over to tie it to our 
web gear so it wouldn't snag in the jungle and the wait-a-minute bushes.

When we would setup for a period of time and had the chance, we would 
use the long whip in place of the tape whip.  This came out of the 
accessory bag that went with the radio set.  It was well over 6 ft in 
length.  It wasn't flexible.  However, it gave us a much further reach 
for both transmit and receive.

When we would have to "phone home", either to update Mother, or arrange 
for an extraction, that was when we strung the dipole of the PRC-47. 
Yes, it too had a whip.  That whip was more for in country use.  Not to 
"phone home".

I've been through both low level RF environments and extremely high RF 
environments.

Both environments were matters of lives and limbs to say the least.

My background was highly varied as I progressed through an entire 
military career.  It proved to be a very interesting experience.

I've done the crawling through the jungle, working with missiles and 
warheads, and then other nuclear devices that were used for power 
production, burst testing to determine effects on living organisms, and 
the creation of Radioactive isotopes for either medical use or standard 
sources for calibration and/or reference.

Shielding and sensitivity for either RF or Radiation are very similar, 
yet the instruments were different.  None the less, all had to be 
calibrated and made sensitive enough to perform in there intended use.

All of this comes into mind and play as I continue to work with a 
variety of test equipment.

Should I really need to get the leakage of RF really down, I switch to 
the HP-3336B.  It is very well shielded, and when used properly, the 
only issue that gets to be watched is the attenuation of the cable 
itself.  Today's RG-58 is a far cry from that used way back when.

Bob - N0DGN