Wednesday, March 2, 2016

Battleship Iowa On The Air NOW With Original Radio Gear! UPDATED

We're up and running on 18.146 right now......


Make that 18.155. Had to move due to QRM....

Should be OTA for the next hour or so.....


UPDATE

I made 10 contacts from coast-to-coast. They all said we had "great audio".

The R-1051's have a front end as wide as a barn door. The specs say "3.2kHz" bandwidth, and I'm guessing that's @ -6dB, but no spec (that I could find in our manual) on the -60dB point, so I don't know the Shape Factor of the filters in it.

Whatever it is, it's NOT good enough for even a moderately "crowded" band.

Signals the we could not hear on our TS-850 came bleeding through on the R-1051 receiver, making it difficult to copy the stations that were calling us.

And we had a huge pile-up after I "spotted" ourselves on the DX clusters.

Next time (next week, I hope) we'll try using the URR-74, as it has selectable bandwidth crystal filters in it.

It's a bit cumbersome finding a frequency that sounds "clear" on the R-1051, and then tuning the transmitter, and then adjusting the antenna coupler down in the transmitter room, but by the time we'd done it a few times,the guys helping me were getting pretty good at it.

We used the "Twin Whips" up on the bridge for the receive antennas, and the "Goal Post" antenna back the #2 stack for transmitting. We were running around 200 Watts output, and found that if we go much lower than that, the transmitter got unstable.

We had very few visitors today, so our "RF Safety Monitor" we posted at the TX antenna didn't have much to report to us.

So, today was a "learning day", and we had fun.

1) The r-1051 receivers are not very selective. We used three different receivers, and they're all the same

2) They desense badly, and take about 2 seconds to recover after you unkey the transmitter. This equipment was never meant to be used like this, operating "simplex", so desense was to be expected. We just didn't know it would take that long to recover

3) The dial accuracy of the receivers and transmitters was very good. We could tune the receiver to one frequency, and tuning the transmitter to the same indicated frequency was "plenty good enough" to use, with only very minor fine-tuning of the receiver required to get on exactly the same frequency as the transmitter. This would be a non-issue if we had the 10 MHz master oscillators that were originally installed, but we don't, so we run the receivers and transmitters using their own internal oscillators

4) The guys in the transmitter room retuned the antenna coupler each time we moved in frequency. I don't know if this is required if we only move 5 or 10 kHz at the low power levels we were running. I'll take one of my antenna analyzers with me next time and see how bad the match changes as we move in frequency. The guy doing the tuning is new at it, he's following the Navy tuning instructions "to the letter", and it winds up taking several minutes to "Peak and Dip" the controls with every frequency change

So thanks everybody for bearing with us! We're still learning about how to actually use the equipment now that we have it functional. We were juggling receiver line-out levels, transmitter line-in levels, antenna tuning, and the lookie-loos who came by to kibbutz while we were up to our rear in alligators!

Next week we should be better at it.

12 comments:

  1. So you figured out how to herd cats. :) Well done.
    Very poor antenna here for 17m. I am hearing some stations working you though, just not hearing you. Propagation to west coast from S. Fla poor this afternoon. Same with a 20 m net I had today at 2000Z.
    Someday....
    Terry
    Fla.

    ReplyDelete
    Replies
    1. I worked two stations in Florida, one of them was mobile.

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    2. If it was raining soup, I would be standing outside with a fork.
      Terry
      Fla.

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    3. Well, they were weak, we had QRM, and one required a relay from a local guy, so don't feel too bad!

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  2. Well done, my friend. It's not easy to retrofit 75-year-old technology, re-learn it, and make it work. Well done!

    ReplyDelete
    Replies
    1. WELL....this is the equipment that was installed during the 1980's retrofit of the ship.

      This is "Gray Radio" gear, as opposed to the 1940's "Black Radio" gear, all of which is either in museums, or the junkyard, or on the bottom of the ocean somewhere.

      We were very lucky in that the Iowa is the only one of the 4 Iowa-class ships that had the radio equipment intact.

      The other three ships had been stripped, especially the transmitter room, which was stripped "to the walls" on the other ships.

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  3. Just found your blog. I was impressed with your using some existing equipment from the Iowa for contacts. I was involved a few years ago in a contest, when I was on the USS Silversides, a WWII submarine located in Michigan, and we made contacts, but we used modern equipment, from the original radio room. It was one of the best experiences of my ham life. I tip my hat to you and your fellow hams. Good job and I am proud of you.

    ReplyDelete
    Replies
    1. We also have two Amateur operating positions onboard. The main station which usually runs SSB is a Kenwood TS-850 connected to the Disc/Cage antenna on the bow.

      The other station which usually runs CW is a Kenwood TS-940 -OR- a Yaesu FT-900 which are connected to the 14' "Trussed Monopole" located on the stern near the helipad.

      I'm the VP and Station Manager of the Battleship Iowa Amateur Radio Association (BIARA), and the Lead Transmitter Tech for the "Gray Radio Gang", which is a separate group concerned with getting as much of the "Gray Radio" gear operational as possible.

      Thanks for stopping by!

      Delete

Keep it civil, please....