The first 955 I bought without a crystal cause I have many new cyrstals here on my channel. I've never not once had a problem buying a receiver and putting my crystal in it (until now). It just occured to me the other night that it could be I simply have a 940 receivcer that's not perfect and a new 955 that's just not perfect. Interesting that both the high end receivers and the two or three low end receivers I have would all work close up, albeit with a few jitters on the non-pcm receivers. But all would fail miserably walking 20 feet from the airplane.

Lee, I'll go 100 paces this evening, I went 75 and I'm in a neighborhood, wasn't much further I could go and still see my Fiance to give me the hand signal if the speed brake popped up in fail safe. At 75 paces I did turn the switch off to make sure it would go in fail safe and it did. I turned back on and danced in circles all the way back to the airplane in pure control and happiness

So, at least for me the lesson learned order my JR receivers "with" a crystal in them. I had heard that before, but my practical experiance suggested that swapping cyrstals was not a range issue. at least till now.

Well, I don't like to be the bearer of bad news, but buying the receiver with the crystal installed dosen't necessarily mean the receiver is going to work at max performance. The reason why JR, Futaba, and the rest of the manufactures try to tell us.... oh, 50 paces (or 50 feet..even worse) is fine.... is precisely because they just pop crystals in most times without checking anything. They will tell you and I Oh... all receivers are tuned to a bench mark so they will all work intermixed and intermingled.

Well, if that is so why is it that no two receivers are the same, and some are dramatically better than others. Hence my reasoning for not assuming anything... the only way to know for sure is test each receiver / transmitter module and compare each to the very best units you have seen. Over time you'll more easily be able to cull out the bad units.

Good luck and keep in mind once you've defined an acceptable Baseline distance, and have a unit that meets or exceeds that distance, the real problem then becomes doing an installation that won't degrade more than about 20% of that distance. Matt suggests 10% which is even a better standard to shoot for.

My minimums for the JR 10 channel series radios (antenna removed) is 225 ft. Baseline, and no less than approx. 190 feet with turbine at full power!! Keep in mind every foot shorter distance means your excepting a weaker RF link.... would you rather have the strongest RF link when some goof ball turns on? Or your batteries get low, or any number of other possibilities occurs? Personally I would rather have the strongest link possible to began with.

My BobCat with the older JR dual conversion 940s receiver gets a measured 330 foot Baseline, with less than 3% degradation at (JetCat P-120) full power. The less than 3% is possible only because I have installed a Rat Trap... (a complete turbine component RFI shielding system).

I am in the process of changing out the JR receiver in my BobCat, and replacing it with the new Futaba 14MZ system. I have yet to do the Baseline range check with the MZ receiver in the BobCat..... I have put the receiver through my three basic acceptance tests, it passed the vibration, and temp tests, but barely passes the 1 & 10 swamp test! And that is a $400.00 dollar receiver!! I really should send the MZ receiver / transmitter modules in for alignment / tuning but I'm not sure the service center even knows how to began to correct or improve the side band rejection tolerance at this point in time. I've decided I would take the time to install it in my BobCat just to see how it compares, apples to apples, to the JR 940s system. I've been flying the 940s for three years now so it is a known commodity, with known distances..... so I'll just expect the 14MZ to match or beat the JR...
Regards,
Lee H. DeMary
AMA 36099