The following information has been received from the manufacturers
on what channel spacing is required,
current sets will operate at 10 KHz, however, they do only supply
xtals at 20KHz Channel spacings, starting at (tba) So these can
operate on either the new 35, or 36 MHz bands.
All current sets will operate at 10 KHz, as will some older sets,
but for safety, it would be wise to operate non- current sets on a
20 KHz channel spacing. So these can operate on either the new 35,
or 36 MHz bands.
All sets must be on a 20 KHz channel spacing, so only the 36MHz
band can be used. However, Hitec sets have not been imported on 35
nor 72 MHz, and in limited numbers on 36MHz. Synthesized modules
(and synthesized receivers) on 36 MHz only, will be brought in for
those with Prism 7X, Eclipse and Optic 6 transmitters.
The following can carry out re-tuning work, as well as any other
service work that may be required.
Trevor Bringhans Ltd,
Auckland. Tel 09 262-3758. Note that they have offered to retune
sets "at cost"
Airsail, Auckland. Tel 09 579-6052.
Communications, Havelock Nth. Tel 06 877 0466 (David Appleton)
Mark Halliday, Christchurch. Tel 03 384-4547
And some model
shops do have local technicians that can carry out retuning, Check
Do not use imported 35 MHz crystals in older
sets. The set may work, but may also be off-frequency, or have too
wide a bandwidth, thus causing severe problems to other users. The
35 to 35.5 MHz band is for 10 kHz channel spacing only. Current
production systems manufactured by Futaba and JR only, at this
stage. Hitec equipment must operate at a 20 kHz channel spacing,
i.e. 36 MHz. If you want to put an older set into this band, then
it is imperative that you:
1. Use only the correct
2. Ensure the set is properly tuned by
a service agent., and is considered suitable, by measurement, to
operate at a 10KHz channel spacing.
You will also want to
be careful with older sets in any event, and the test written by
the British Model Flying Assn. some years ago is an easy and
effective way of doing this:
The check is quick and
easy to do. Flyer A switches on transmitter (with aerial down),
then switches on his receiver and stands about 4 metres from his
model. Flyer B, on an adjacent channel, switches on transmitter
(aerial up) and stands alongside flyer A. No interference should
be noted on A’s model and it should be under the full control of
A’s transmitter. The test is then repeated using B’s model and
with his transmitter aerial down and A’s extended..
interference noted indicates possible tuning or crystal problems
and must be investigated further. The test may save your model, as
it will give early warning of problems beginning in your radio
equipment, usually well before they become bad enough to cause
control problems in the air.
If there is any doubt, or
the above tests show any sign of interference, take the peg either
side of the one you are operating on, for an extra safety margin.