Transmitter Hunting in the San Francisco Bay Area
5th Saturday, Jammer Hunt
March 30, 2002

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Last updated: Saturday, March 30, 2002

Mar. 30, 2002 "Jammer Hunt"
(Saturday) at 10:00 AM
Pleasanton Start Point.
Talk-in 440.775(+) PL 118.8
Paul and Tina will be the Foxes for this Jammer Hunt.
This will be a challenge hunt and will not conform to the Pleasanton Boundaries.

Please PRINT instructions below.

 

PRINT INSTRUCTIONS

JAMMER HUNT - March 30, 2002 - 10:00 AM - Pleasanton Start Point. Talk-in 440.775(+) PL 118.8

Lately, the 147.455 repeater has been getting jammed by an unknown jammer. It all started when a new ham named 'Alpha' got on the repeater who also happens to have a horrible speech impediment. Alpha's impediment is that his voice sounds a lot like beeping when he talks (O.K., so he sounds like a fox transmitter, work with me...) Our jammer began mocking poor Alpha by imitating Alpha's voice which sounds like beeps, possibly recording Alpha and playing it back over the top of Alpha's transmissions. The jammer always waits until Alpha is talking, then keys up over Alpha and plays beeps over him. Anyway, we have information that the jammer will come on at 10:00 AM on March 30th. Alpha has secretly agreed to 'bait' the jammer while you T-hunters find him. The repeater input frequency is 146.565, so you should monitor that for the jammer. He is either mobile or base since he has a strong signal into the repeater and easily covers up Alpha.

Your mission is to first: locate the jammer. If he's mobile, get his license plate number and write it at the bottom of this sheet. If he's a base, get the address and write it down on the bottom of this sheet.

Second: Locate Alpha's QTH and write it down so you will know where to send a copy of the information you gather.

Last: Locate the repeater. The repeater output frequency is 147.455 MHz. Since Alpha will be talking into the repeater a lot and the fact that the repeater has a ridiculously long carrier 'hang time', it will stay keyed up almost continuously, so it should easy enough for you to find it. The repeater trustee (let's call him 'Paul') will be waiting for you at the repeater for your information.

Shortest round trip mileage counts. Ties (10% rule) will be broken by time of arrival at the repeater, so it will be realistic that waiting too long to find the jammer could result in his leaving the air before you get him. The repeater to use during the hunt would be 440.775, PL 118.8 Hz. Paul will be monitoring as well. If you have to drop out of the hunt, please let Paul know.

Good luck hunters!

PAUL & TINA

Jim's TIPS & HINTS

1)  Plot all three initial bearings. (Note their signal strength and whether it is vertical or horizontal).
     a) The repeater is on 147.455 MHz.
     b) The Jammer and Alpha, on 146.565 MHz. They'll both be on this frequency.
          1) Take several bearings to see if the Jammer is mobile.

2)  Program your U-R-Here radio.
     a) 146.565 MHz. has a third harmonic of 439.695 MHz.
     b) 147.455 MHz. has a third harmonic of 442.365 MHz.
          1) Note: this frequency is the CLOCK crystal for many computers, so don't chase a computer.

3)  Pick your first target. Probably the Jammer but, don't forget Alpha, he might be closer.
     a) The Jammer and Alpha will probably be transmitting at the same time.
         1) FM receivers capture, so hunt the closest or strongest signal first.
     b) Identify each transmitter, listen for characteristics that make each transmitter unique.
     c) The Repeater should be last, since this is the end point. Total mileage counts.

4)  Progress slowly, plot bearings to all three transmitters, don't drive past your target.
     a) The biggest mistake in plotting, is to think your target is further out than it really is.
          You need to eliminate your current area, then proceed further out.

5)  Doppler hunters have the edge here. If you sit still for a few minutes, you can tell if the Jammer is
     mobile. Watch your Doppler dial for movement.

6)  Caution: if the Jammer is mobile, don't chase him. This could be dangerous. Complain to Paul on
     440.775+ PL118.8, that the mobile Fox is eluding your efforts to write down his vehicle license.

7)  This hunt will take time, so don't get frustrated or quit. If you have to leave the hunt, call Paul on
     440.775+ PL118.8 and let him know. If you get frustrated, find the Repeater FOX and wait for the
     others.

Good Luck.
Jim Sakane - KD6DX

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