[Milsurplus] VHF Radio at Battleship Cove, MA(long)

[Rob Flory]

VHF Compartment at Battleship Massachusetts

March 15-16, 2008 Brown Beezer W1NZR, Battleship Curator Chris Nardi N1UXJ, and Rob Flory K2WI worked on restoration of equipment in the VHF compartment aboard BB-59.  The compartment is located on the 04 level in an area that was part of the Combat Information Center during the WWII configuration of the ship.  

In the compartment are found 4 TDQ transmitters, 4 RCK receivers, 2 AN/ARC-4 transceivers, an ATC transmitter, and 2 MAN transmitters.  The ARC-4s and the ATC are powered by “homebrew” power supplies that were built on the ship with ship-wound transformers and  Tungar rectifiers.
This equipment is intended for use for communications with aircraft, with the likely exception of the MAN equipment.  

The weekend’s first project was TDQ number 3.  The RF deck was pulled first and gone over.  One tube was replaced as the getter was solid white.  The others were pulled out and cleaned.  A missing 807 was replaced in the oscillator.  Meters were installed from a donor unit.  Switches were cleaned with contact cleaner.  Two crystals were installed, a newly-manufactured one and an original TDQ crystal on 144.360Mc.  The blower was spun by hand to see that it was free.

The modulator deck was next.  It had a meter installed from a donor unit, and a couple of missing tubes replaced.  The test key contacts were cleaned.

The power supply unit was pulled and inspected.  A mount for a cartridge resistor was broken, but having no rapid-drying glue available, the resistor and its mount were lashed into place by its wires, using cable ties.  While the power supply unit was out, the rack wiring was inspected. 

Once we got it set for local control, it powered up, with the blower reaching normal speed after about 2 minutes of slow turning.  It tuned right up and made 20 watts into a dummy load.  The low power output was attributed to a weak final tube at first, until Brown noticed we were still in Tune position.  Once we switched to Operate we got about 40 watts.  A T-17 microphone was borrowed from Radio II, and after some cleaning of the jack with a plug soaked in contact cleaner we were able to key the radio and modulate.

The morning of the 16th, Rob powered up RCK number 1, and got nothing but hum.  Moving on to number 2, it produced noise in the phones, with a peak when the tuning control was set to the crystal frequency.  A short piece of wire was installed for an antenna while the TDQ was warming up.  Once the TDQ was warmed up a test transmission was made with a dummy load, which was heard on RCK number 2 with good strong audio.
RCK number 3 would not light up at all on power up.  On the bench, tracing of the primary circuit revealed that the 115V tap on the power transformer had separated.  The 120V tap was selected instead, and the receiver came to life.  It heard the TDQ well.  

Number 4 also would not light up, and the problem was found to be a corroded fuse.  It powered up, but no noise peak was heard when the tuning control was set to the crystal frequency.  It could hear the TDQ but weakly.

Remote control of the TDQ was attempted from Radio I.  It did not power up when patched to a radiophone unit, but when patched to an LOP, the transmitter was able to be powered up, and the keying relay operated when the key was keyed.  The semi-break-in relay did not key up the transmitter, probably because of dirty contacts, but that was not investigated further.

The antenna feedline for TDQ 3(and likely the rest of them) was found to terminate on the 09 level in the SG radar transmitter compartment.  From there a new section will have to be installed up the mast, and an antenna installed.

System integration work will have to be done.  It will be necessary to wire the receiver power to the associated transmitters, so that they come up together on remote control.  Receiver audio and squelch control wires will have to be installed locally, and their connection to the patch panel in Radio I verified. 
 
Later work on RCK 1 at Rob’s shop revealed an IF amplifier tube with a screen-suppressor short.  Replacement brought the receiver to life.  Further testing will be done on the bench and on the air.