[ARC5] TBS Radios (VHF for PT Boats)

[Mike Morrow]

Dennis wrote:

>Hmmm...  The account relates "excited chatter of the Martinis (PT  
>boats) on the TBS tactical radio...."  PT boats carried TCS radios.  
>Were they equipped with the TBS also?

The following is from a 1945 USN publication "Know Your PT Boat" found
at http://www.hnsa.org/doc/pt/know/index.htm .

----------------START EXCERPT ----------------------------------------------
Notes for Radiomen. 

8. Your VHF is not as secure as you perhaps assume. Transmissions over VHF have
gone 400 to 500 miles beyond the horizon. PTs operating reasonably close to enemy
territory or units can give away their position and valuable information by useless
chatter over a VHF circuit. And remember, you are not the only pebble on the beach.
Our planes use it extensively.  Unnecessary PT transmissions must not clutter up
communications of a vital operating aircraft squadron. You may think the air is
clear because you do not hear any transmissions, but, remember, they may be
receiving you several hundred miles away where they may be making a strike. So do
not depend on the term "line-of-sight" transmissions. It is not reliable at all
times, hence guard the use of your VHF set much as you do the TCS. Jam sessions,
razzle-dazzle cowboy stuff, and hot-shot vocalizing are all very amusing to you
if you are a lunk head. Just consider the harm you can do to yourself, your
shipmates, and our aviators and you will be sure to knock off all unnecessary
transmissions. Even when another boat in your section cannot hear you, your
transmissions may carry to out-of-sight areas where the enemy may be listening. 
Transmission security for both radios is greatly enhanced by the use of
follow-the leader tactics, basic formations, and courses established before
leaving the base, and prearranged rendezvous points and times if the boats
get separated. When PTs operate in sight of land, special care must be taken
in VHF transmission. The Japs have many monitor stations on land and they have
made many experiments with VHF type of equipment. It is to be expected that they
are aware of our approximate frequencies. Give a Jap station enough transmissions
and a shore battery will be laying a shell in your cockpit. For valuable aids in
operation and on your equipment see MTB Communication Manual, 1944.  
----------------END EXCERPT ----------------------------------------------

The above discussion contains this caution about VHF usage:

"And remember, you are not the only pebble on the beach.  Our planes use it
extensively.  Unnecessary PT transmissions must not clutter up communications
of a vital operating aircraft squadron. You may think the air is clear because
you do not hear any transmissions, but, remember, they may be receiving you
several hundred miles away where they may be making a strike."

This seems to positively indicate that VHF on PT boats, at least by 1945, meant
something like the AN/ARC-4 (or even a SCR-522/624 variant) in the 140 MHz range,
just as these sets provided similar capability for US submarines.

In any event, it appears the PT boats had some sort of VHF set in addition to the
TCS.  Were the PTs at the Battle of Suriagao Strait in late October 1944 equiped
with the same VHF as PT boats in 1945?  I don't know.  Even if they used something
on the old "talk-between-ships" band of 60 to 80 MHz, was it a a TBS?  I'd suspect
that a MBF would be more likely.  The MBF and (IIRC) TBS needs 115 vac or 115 vdc.
Did a PT boat even have 115 volt power?

As far as this article written by Admiral Holloway goes, I would bet that the reported
radio chatter actually took place on MF/HF, provided by the TCS.  I doubt that a PT
had a TBS (or even MBF) as its VHF set.  

It's frustrating that the many sites dedicated to PT boats seem to consider details
about the radio gear to be uninteresting technicalities.  In that respect they are
just like so many WWII aircraft "restorers" and operators.

Mike / KK5F

BTW:  "Naval History" magazine, the source for the article that is being discussed, is
a wonderful magazine.  It is published by the US Naval Institute (the professional
society for US naval officers).