Arizona Emergency Net - Maricopa

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This site currently includes recordings from 2010-2012


Every Monday night, the Arizona Emergency Net – Maricopa meets on 2 meters FM for training and exercise in the public service communication arts. We focus on preparation and readiness for public service – be it scheduled events like bike races or drills, or emergencies such as storm damage or terrorist attacks. Someone has to be ready. This net is dedicated to addressing that challenge. The Arizona Emergency Net – Maricopa also activates during threats or emergencies affecting Maricopa County

3-29-2010 - Smoke Test - AK7RB


The topic was "Smoke Test"

This was time to turn up our stations to maximum power and see how it performed.

We had 26 stations that participated in the net. We checked in by the maximum power level being used. 8 Stations were transmitting 5W or less, 15 were transmitting 45-50W, and 3 stations were transmitting 100W or more.

During the check-in process, all stations practiced listening on the reverse repeater frequency to see how many stations they could copy if this net was running simplex. 18 stations participated in monitoring the reverse frequency. Of those stations, the average number of stations heard was 9, with the maximum heard being 20. Those stations that could hear more than 10 generally used roof top mounted or raised antennas. The station that could receive 20 stations has a Diamond X510 at 30 feet with a receiver amplifier.

Since the FCC rules require us to transmit on the lowest power possible to have effective communications, we discussed when high power meets that requirement. Answers included when running a simplex net over a greater distance between participants (such as when the repeater fails, and we all have to switch to simplex), when your making an emergency call and need to be heard, when using the auto-patch, when there are obstructions to your signal path, and to overcome large cable losses.

We discussed the "Capture Effect" which in FM transmissions is that only the highest power signal received by an FM receiver will be demodulated. We talked about how we can use high power to take advantage of this phenomenon. Answers were for the Net Controller so that he wins all doubles, for emergency communications, and to overcome both unintentional and intentional interference. (Handy to proceed on a net with an open mic).

We also discussed the disadvantages of high power, which included reduced battery life, equipment stress, increased RF exposure, and creating local interference.

Finally, alternatives to higher power to boost communications effectives were discussed. The most bang or the buck is a better antenna. Having it higher, or having more gain, better feed lines, or more directional were all suggested antenna improvements. The advantage of a better antenna is that is also makes your station a better receiver.

I want to thank Andrew, Kf7CCC, for volunteering as Alternate Net Control.

The topic next week is "Guard Channel Operations".
73's AK7RB
Net Control

Categories | AEN-MAR Weekly Net


Filetype: MP3 - Size: 7.02MB - Duration: 1:01:21 m (16 kbps 8000 Hz)