Thursday, February 12, 2015

More Battleship Iowa Transmitter Progress

Well, we now have three "functional" transmitters after this Wednesday's work.

We found a dead 6AN5 tube in one the exciters, but replacing it didn't seem to help the output, so that one still needs some repair work.

And we still have to replace the chain-drives from the frequency set knob to the internals in most of the exciters, or at least in the ones that we can get up and running with enough drive for the power amplifier.

The original "chains" were little plastic things that look more like ladders than what you'd think of, and after sitting for 25 years in one position the plastic took a set, and turning the knobs results in the "rungs" getting ripped out of them.

We're slowly replacing them with real metal chains (like miniature bicycle chains) that our friends on the carrier Midway donated to us. Our lead Gray Radio Guy was down there last year, and noticed a bunch of exciters that were going to be scrapped, so he asked if we could salvage some parts. The guys on the Midway stripped out the chains, sprockets, and detent mechanisms and sent them our way, so we have a small supply of them now.

We also have some plastic chains, but I haven't talked to our guy who does the work to see if, or how well, they work.

And we're debating whether to home-brew a mast oscillator for all the transmitters and receivers so they're all on the same frequency.

I have several 5MHz Oven Controlled Crystal Oscillators here from some HP test equipment I stripped, and it would be a simple matter to box one up with a power supply, and feed it to the distribution amplifiers that are still in place.

The cables that used to bring the 5MHz master clock down to the transmitter room from Radio Central have been repurposed to connect the two portions of the bow-mounted Disc/Cage antenna up to Radio Central, so *if* we decide to set up a Master Oscillator, we'll have to mount one in Radio Central for the receivers, and one down in the transmitter room for the exciters.

And we had a group of SeaBees aboard from Port Hueneme in the morning, and one of them was an ET, so we took him around all the radio gear, most of which he knew.

Still much work to do in getting the antennas and cabling sorted out so we can run both the Amateur Radio station and the original gear, but we're starting to make some definite progress!


Keep it civil, please....