It is getting harder all the time to find and buy new pairs of crystals of any type as they are now considered more or less obsolete.

I have a good stock of new and unused crystals (mainly MPX) to cover most frequencies in the 40 and 41meg frequency ranges (and some 35meg too).

For some of the frequencies I have multiple receiver crystals to allow the use of a single transmitter with several different models.

If anyone is in need of a new set of crystals please contact me by email as I may be able to help you find what you need.

These will be listed on eBay eventually (when I can get around to it) but for now I have almost every frequency available so I should have whatever you may need.

When fitting any new 40 meg crystals into any radio it is always good practice to do a "ground range check" with the tx aerial retracted to make sure everything is working correctly before launching your model.

This is particularly important when fitting "non-standard" crystals (not original make or type) just to make sure that everything is working well and safely.

To add to this 40meg radio discussion.

I have fitted and used Mutiplex radio crystals in Futaba (and others) for many years and never had a glitch.

Multiplex (often referred to as MPX) crystals were always the most expensive to buy here in the UK and were claimed to be "superior quality" (by their German sales representative) ........."but they would say that wouldn't they".......

I have also used 41meg crystals in my radios with absolutely no problems whatsoever.

Hi Colin, if you need to buy 40 Mhtz crystals make sure they are FM. The only use for 40Mhtz AM crystals is for the 2 ch sets. All else at this frequency is FM.

Roy

In addition for anyone looking to get into submarines 35/40Mhz penetrates water far better than 2.4Ghz.

Thanks Roy, I nearly binned all my 35mhz equipment as nobody wanted it when I gave up flying.
Cheers Colin.

Hi all, The 40 Mhtz and 35 Mhtz frequencies are quite close electronically. This means that if you put a pair of 40Mhtz FM crystals into a 35Mhtz set it will work at the new frequency of 40 Mhtz. The receivers with dual conversion will need a dual conversion rx 40 Mhtz crystal.

So is this a bodge? No, it isn't!

My Fleet 40Mhtz RC sets one of which was bought by myself from the shop is labelled 35Mhtz underneath. The box it came in is labelled 40Mhtz.

The 35 Mhtz. Futaba multi channel TX with a 40 Mhtz crystal operates Hitec and other Futaba receivers sold for 40Mhtz use. The same goes for my Fleet equipment.

With the standard Futaba 35Mhtz receivers with a 40 Mhz crystal fitted also work from Hitec dedicated 40Mhtz transmitters.

Remember that you do not have to match a 6 ch. Tx to a 6 ch. Rx. You can operate a 3 ch Hitec Rx from a 6 ch Tx also a 3 ch Hitec Tx will operate 3 of the 6 channels of a 6ch rx, well you may have fun finding out which ones but it is generally channels 1,2 and 3.

The only area I would be careful of, is bringing Fleet rx's into use as these have non-standard servo connections with the red and black transposed, a careless moment here writes off the rx. But a model boat fitted out with Fleet rx and and servos will operate from a Futaba 35Mtz Tx with a 40 Mhtz crystal fitted,

All the above I have tried out except the dual conversion rx and it is all interchangeable as I have described.

Newcomers, by all means go for the 2.4Ghtz sets but the old stuff still works! The crystals are all available on-line.

I do not recycle everything but please do not throw away these beautifully engineered transmitters as they still have a working life in them.

Regards

Roy