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Much has been written in the ZipZap forums regarding using longer antennas to increase
operating range. The general concensus is that the longer the antenna, the greater
the operating distance. Little at this point has been said about antennas cut to
the resonant operating frequencies of 27 MHz and 49 MHz, which theoretically would
produce a more effective antenna system for both the transmitter and receiver.
Admittedly, for use on ZipZaps this could be technological overkill. But if
you're the experimenting type, try cutting your antennas to the lengths listed in the
table below. The length should be measured from the antenna connection at the
printed circuit board to the end of the antenna.
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Below is a table showing resonant antenna lengths for the two ZipZap operating
frequencies.
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| lambda |
length, in
(27 MHz) |
length, in
(49 MHz) |
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| 1/4 |
104.00 |
57.31 |
| 1/8 |
52.00 |
28.65 |
| 1/16 |
26.00 |
14.33 |
| 1/32 |
13.00 |
7.16 |
| 1/64 |
6.50 |
3.58 |
| 1/128 |
3.25 |
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Radio Shack offers the following telescoping replacement rod antennas which, with one
small modification, will be suitable for use in any of the ZipZap controllers.
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| part number |
extended length |
price |
| 270-1401 |
5 sections, 30-1/2 inches |
$3.99 |
| 270-1402 |
4 sections, 34-3/8 inches |
4.49 |
| 270-1405 |
5 sections, 28 inches |
4.49 |
| 270-1408B |
6 sections, 72 inches |
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The mounting/retaining hole at the bottom of these replacement antennas is in the center
of the pad. The hole in the original controller antennas is offset to one side.
While drilling another hole in the replacement antenna is an option, I found it
easier to cut a slot in the mounting pad. Taking a Dremel tool with two cutoff
discs stacked together, I cut in from one side of the pad as far as the existing
mounting hole, effectively putting a slot in the pad into which I could put the
mounting screw.
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