SrTelemaster150

I have a couple of 72mz Hitec PCM Rxs, 1 of them NIB ad well as 2 PPM Rxs.

All 3 of my radios are both 72mz & 2.4gz capable through Spectra/2.4gz modules. I don't see any reason to not keep using the 72mz Rxs.

I want to buy a few spare Crystals since they are getting hard to find. I can get Hitec single conversion crystals for my mini Rx but dual conversion crystals no longer seem to be available from Hitec. I can however get Futaba dual conversion crystals.

Since Futaba Rxs will work W/Hitec Txs, it would seem that the crystals would also work.

Can anyone shed some light on this?

Truckracer

My Feedback: (19)

I don't know if it was correct practice, but I use to use those crystals interchangeably and with zero problems. Of course Futaba and Hitec said not to do it.

A.T.

72MHz have proven to be interchangeable between Hitec & Futaba 72MHz only.
Other crystals are no longer interchangeable between brands.
Contrary to popular belief they are totally different in cut, overtone value and a few other specs.
e.g. Hitec DC RX crystals on 35.36 & 40MHz have a frequency 10.7MHz ABOVE the nominal frequency whereas
Futaba DC RX crystals are 10.7MHz BELOW nominal frequency.
Hitec FM TX xtals are cut at half nominal frequency whereas the Futaba FM TX xtals are cut at 1/3 nominal frequency.
With single conversion RX, whilst you may get reasonable results in good conditions with Hitec xtals in Futaba RX.
Hitec crystals must be used in Hitec RX for optimum results.
Futaba single conversion RX crystals may appear to work but with proven less range and glitching,
especially noticeable in damp weather or wet ground.
Local radio technician was surprised but ran a number of tests with result he is also now convinced that there is a significant difference
in the crystals as has also been confirmed by the local crystal manufacturer who supplies USA military and others requirements.

Be aware that the Futaba crystal cases are larger than Hitec, the crystals do not fit within the Hitec crystal covers
or use with rubber anti vibration "boots". The pins are also slightly wider apart so are a tight fit.

For further information, refer to:
. Crystal compatibility between brands

Alan T.
Alan's Hobby, Model & RC FAQ Web Links

SrTelemaster150

So from the above it seems that Hitec & Futaba 72mz DC crystals are interchangeable but SC aren't?

I can get Hitec SC crystals but not DC. For DC all I can get are Futaba.

Truckracer

My Feedback: (19)

From reading the many words ..... that's the way In interpret it!

By the way, my Futaba and Hitec DC crystals are exactly the same package size, pin spacing, etc.

Rod_Hart

My Feedback: (4)

If you need crystals try here.

Rod http://www.radicalrc.com/rrcxtalexchange.html