[Hallicrafters] USS North Carolina after action report

[Mike Everette]

The Battleship North Carolina was indeed on the air Saturday afternoon (1-15) from about 1:37 pm until 4 pm EST.  We stayed on 40 meters the whole time.  The TBM-4 transmitter was used; it seems that tuning this rig (a big, BIG black monolith!) on 20 meters is a bit touchy, plus it takes the transmitter's master oscillator a long time to "settle down" and the effect gets more pronounced with increasing frequency due to frequency multiplication.  Those issues figured into the choice of bands.  

We were running the transmitter at "low power" or around 100 watts out; it's capable of 400 to 500 watts, but the 861 final tubes are very scarce and they don't want to push it.  Plus, there may be a risk of overstressing the old motor-generator set;  "spitzensparken" are not a desired phenomenon.

The number of contacts was rather low, about 8 complete to be exact and several more that didn't complete due to QRM -- mostly from digital stations that (dare I say it) seemed to gang up to run us off the first choice of frequency, 7035 KHz.  We moved up to about 7044 and things went a bit better.  Since there was not an abundance of people calling us, we did a lot of rag chewing, which was great fun.  

We got consistent T7 and T8 reports, which could be caused by one or more issues.  Could be SWR...?  Could be a funky tube...?  Could be a mistuned multiplier stage...?  Could be a bad bypass cap somewhere...?  Could be that something needs better grounding...?  Who knows?  The ship's radio crew tells me that the TBM-4 works perfectly on 80 meters but the "growl" modulation gets worse as the frequency goes up.

This isn't a quick-shift transmitter.  If it's moved even 2 or 3 KHz from where it has been tuned up, a great deal of retuning needs to be done on all the stages.

We had to therefore pick a frequency that seemed clear, then hope "if we call them, they will come."  Well, a few did; and we heard some excellent signals but not very far away.  The best DX was Boston.

If we missed you, some of the problems were due to local QRM of an audio nature.  The RBC receiver was on a speaker, and tour groups came through the area several times.  Lots of people talking in the radio area while we were on the air made copying difficult.  Also, the operators (me included) didn't really have time enough to become familiar with the receiver before actually going on the air.  

The original plan was to operate until maybe 4:30 or 5 pm, but the fact that it was getting real cold down there -- big firebottles notwithstanding --  sort of prompted us to shut down a bit early.

Sorry we didn't get on 20; it seems that a number of folks were listening for us there.  I don't have a clue what transpired with the SSB station; they were set up in a different radio room a deck below where the CW station was located.  Obviously they weren't using vintage gear....

I hope to be allowed another opportunity to operate from the USS NC in the future.  It definitely was a fun way to spend a Saturday.

73

Mike
W4DSE