Frequency Marking

of MOBILE ANTENNAS

Dave Ingram K4TWJ Eastwood Village 50 North Birmingham AL 35210

I operate mobile a good bit, and I like the ability to move from one end of the band to the other. Also, when 1 move the rig between my two cars [ take the Hustler resonators with me.

All this calls for retiming the resonators for a low swr, which is time consuming.

Although Newtronics supplies their resonator tip rods with a "split pea" type of marker (which you move to mark your favorite frequency) this is good ior one setting only. What if you want to mark the whole band, every 100 kHz, or for two cars (which never seems to fall at the same setting of the resonators)?

My solution was simple . *, after finding the point of resonance, I filed a small notch into the tip rod, with the edge of a file, A slight notch on one side of the rod is easily spotted, and in no way hampers operation of the resonator.

My 40 meter resonator, which has notches for car No. 1, car No. 2, CW, mid-band, and phone portions, somewhat resembles Jesse James' gun handle, but I can move from car to car, or from phone to CW without worrying about swr, and know my signal is at its best.

A word of caution keep a list in the glove compartment of which notches are for wha: frequencyj lest you have to get out the trusty swr bridge and go over it again.

This system, while used on my "Hustlers,'1 would work just as well on any of similar antennas.

Claude Wiatrowski K9AAC/7 3401 N. Columbus Blvd. Unit 7

Tucson AZ 85716

The prices of both digital and linear integrated circuits have fallen so quickly in the past few years that it now costs more to build certain electronic systems from discrete components than to buy the equivalent integrated circuit. This article describes just such a case: the use of digital integrated circuits in a synchronizing generator for an amateur television station. This is not the usual sync generator probably found in the majority of amateur television stations. It generates the same sort of synchronizing, blanking, and drive signals that commercial television stations generate. Equivalent sync generators using vacuum tubes are found in commercial stations to this day. They are notoriously unstable, difficult to adjust, consume upwards oi 450 watts of power, and may fill one or two large relay racks. The integrated circuit version described in this article is extremely stable, has only five easily set independent adjustments, consumes a little over one watt of power, and will fit behind a standard rack panel. More remarkable is the fact that the total cost of the unit is under fifty dollars.

Now, if you are interested in contracting a sync generator, I will assume thai you have

0 0

Post a comment