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Author Topic: What was this used for?  (Read 5966 times)
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N1BCG
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« on: January 25, 2015, 12:35:38 PM »

Unlike my last post asking for assistance in identifying a "mystery device", this one is more about the application. I found a semi-circular circuit board labeled "High Frequency Beacon Transmitter" with an RF oscillator and buffer stage. I swept the circuit with a low level signal from 1 to 30 mHz and noticed a sharp increase in gain in the 21-26 mHz region. The tuned circuits seemed to adjust well around 23 mHz. It puts out about 20 mW into a 50 Ohm load when supplied with 12 Volts.

What could it have been used for?


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W2VW
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« Reply #1 on: January 25, 2015, 12:49:52 PM »

Somebody threw something similar to that on W2VJZ's property a few years back.
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w1vtp
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« Reply #2 on: January 25, 2015, 01:05:21 PM »

Somebody threw something similar to that on W2VJZ's property a few years back.

Threw it on VJZ's property or did it work its way up from below, like a Zombie part BWAH_HA_HA_HA
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K1JJ
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« Reply #3 on: January 25, 2015, 02:31:14 PM »

Peaks at 26 Mhz?

Could it be an original Dave-Made prototype, prehistoric vintage?   Wink  


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Steve - K4HX
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« Reply #4 on: January 25, 2015, 05:41:49 PM »

Clark must be bored.
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WD8BIL
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« Reply #5 on: January 25, 2015, 06:41:08 PM »

I think it's a high frequency beacon transmitter!
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N1BCG
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« Reply #6 on: January 25, 2015, 07:36:33 PM »

Clark must be bored.

I can see how I'm becoming known for these superficial posts...

This is one of two devices I've had for years (so long I can't remember where I got them) and wondering what they were used for is wearing on me. Thanks, Budley, it indeed *is* a high frequency beacon transmitter, but *what* would it be used for given it's unusual shape? I've already spent too much time searching online for answers, so I'm hoping that someone will provide that magic "ah hah" keyword.

"Alien" won't be one of them, I'm sure...
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Pete, WA2CWA
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« Reply #7 on: January 25, 2015, 10:09:17 PM »

Could have been used with a buoy or some type anchored float serving as a transmitted navigation mark, to show/identify reefs or other hazards.
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Steve - K4HX
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« Reply #8 on: January 25, 2015, 10:12:30 PM »

Made on 2-11-69.

I think it's a high frequency beacon transmitter!
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KA2DZT
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« Reply #9 on: January 25, 2015, 10:55:11 PM »

Could have been used with a buoy or some type anchored float serving as a transmitted navigation mark, to show/identify reefs or other hazards.

That's exactly what I was thinking, especially with the round shape.  Fit into some type of watertight cylinder housing.
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KA0HCP
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« Reply #10 on: January 26, 2015, 06:18:00 AM »

Doesn't match any USN application I can think of.  Sonobuoys transmit in mid VHF freq.   There are very few marine HF beacons, and other than in training, I never used any aboard ship for actual navigation (in the days before GPS).
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K3ZS
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« Reply #11 on: January 26, 2015, 11:48:07 AM »

Tethered buoys just offshore that record wave heights and wavelengths transmit on 25Mhz to 35 Mhz usually to a weather station nearby on shore.    Saw one on San Nicholas Island many years ago.   Could be what it is.
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