Corona 36Mhz Receivers & Xtals

[ben_fry2003]

I am very interested in the Corona 36Mhz single and dual conversion receivers. There has been some discussion in other threads but I will post here.

Anthony when will you be listings Xtals in the 36Mhz range for these receivers?

Also there are no 36Mhz Xtals for the Blue Arrow receivers when will these be added?

[MartinL]

Try the Hitec dual conversion xtals..it works for me...

[Kentucky]

Not much luck with Hitec Xtals in my Corona RD620. :rolleyes:
Futaba or GWS dual conversion is what Corona recommend.

United hobbies, were are the Corona xtals for 36meg? or any other freq for that matter? :( :( :(

[olmod]

Latest email today informs me that they are waiting on certified xtals from Corona and there is nothing they can do to but wait :rolleyes:

[Magrat]

Not much luck with Hitec Xtals in my Corona RD620. :rolleyes:
(

Could you explain what you meant?

Is there a problem with the Corona/Hitec combo?

This is what I intended to use as I have some Hitec spares.

[Kentucky]

The Hitec Xtals is the only one I have tried.
First a range test was done in the backyard and all seemed fine, the Hitec xtal in the Corona does work.

I then tried the Corona in an indoor model at our regular hall.
This would be a good test since we usually fly with 4 tx's switched on fairly close to each other. This would test for noise and adjacent signal rejection.
Basically it performed pretty badly with frequent major glitches.

This is an email from Corona:

"Dear Ken,
Thanks for purchasing our products.
The best choice of the crystal will be Futaba’s.
Our receivers are compatible with Futaba and GWS’s crystal. As for HITEC or JR, sorry we haven’t made a rigorous test on them.
Corona has crystal of 72MHz and 36MHz now and 36HMz will be available soon.
Have a good day!
Tanya"

To be fair more testing has to be done and I have a Futaba xtal on its way.
If you already have a Hitec xtal give it a go it may work for you just be careful, the model I am testing this rx on is made of EPP and it doesn't matter if it hit the deck.

I let you know how the Futaba compares.
I recall someone posting that a GWS xtal is working well but I'll have to wait a bit longer to get one on my freq.
Let's hope the Corona certified xtals will be available soon. :rolleyes:

[olmod]

Yep I think United/Corona has dropped the ball on this game of will we get the xtals before the chinese new year? and probably wont see them for a month :(

[MartinL]

My 8 channel/Hitec xtal 36 mhz seems to be ok. My 1st set of Hitec Xtal had intermittent glitching, someone informed me that Model Engines had a bad batch of Hitec Dual Convension Xtal, I replaced it and it seems to be OK now????????
More testing..never try it indoor.

[Kentucky]

The xtal I used was from another Rx that had been working perfectly.
The glithing I was getting with the Corona was happening almost predicably when another TX was in closer proximity to my plane.

[olmod]

Ken you have the same results as BLC's testing in regards to adjacent chanel rejection he has tried quite a few different d/c xtals.

[Chris F]

I now have two Corona 8 channel DC Rx's to use with a JR Radio and have tried GWS crystals. Everything worked but the throttle so I've had to shelve them until I can get some crystals that work. Would it be worth trying a Futaba crystal if I'm using a JR radio? Has anyone here found a crystal combination that works with a JR Tx?

Chris.

[MartinL]

Are u sure the Rx is at fault if Esc does not function properly..it could be end point of some Chinese Esc. I m more concern with bad glitching in flight.

[Chris F]

Are u sure the Rx is at fault if Esc does not function properly..it could be end point of some Chinese Esc. I m more concern with bad glitching in flight.
I changed to an other Rx and everything works. I'm more concerned in getting the motor running with the Corona ;)

[Guz]

Go get a Futaba Rx Crystal and give it a try. The Tx isn't the issue, its the tolerances of the Rx Crystal that's important.

Remember, you can have Hitec Rx with a Hitec Crystal, and it will work with your JR Tx.

You may even have an out of spec GWS crystal, again try another one.

[Chris F]

Go get a Futaba Rx Crystal and give it a try. The Tx isn't the issue, its the tolerances of the Rx Crystal that's important.

Remember, you can have Hitec Rx with a Hitec Crystal, and it will work with your JR Tx.

You may even have an out of spec GWS crystal, again try another one.

I have read here on RC Groups many conflicting things about crystals that confuse me. Some say that you should only use a Rx and Tx crystal made by the Rx and Tx manufacturer. Some say you should only use Rx's and crystals made by the manufacturer of the Tx. I have heard other things too, but obviously a lot of this information is incorrect as I use SC Hitec and Jetti Rx's with either JR or GWS crystals with my JR Tx. GWS also has a compatibility chart showing the compatibility of some crystals with theirs. Is there a more universal crystal compatibility chart available? I would rather not go buying crystals on a trial and error basis if I don't have to.

Wouldn't it be a great thing if we could make a crystal compatibility chart of all available crystals here on RC Groups using member’s experiences (success/failure)? It would be a good guide as to which crystals would be worth trying rather than a definitive reference.

[Guz]

Yea a chart would be awesome.

But the basic reason why you stay with matched Rx and crystal manufacturers, is that this the only way the Rx manufacturer can guarantee things work. Which is important when you're playing with expensive toys :p

The manufacturing of crystals is a bit a black art to me. But the way it was explained to me was that each Rx manufacturer build around a specified crystal to vibrate at specific frequency. The actual manufacturer of the crystals does quality control to make sure that they ship the proper crystal to the proper client. You don't think that Hitec or Futaba actually manufacture their own crystals? The order them.

Corona did their design around something close to a generic crystal. They more than likely then tested with Futaba and GWS crystals and found that they are really close to what they originally designed around. Thus they recommend that you can use either their brand of crystal or 'get by' Futaba ir GWS. But truthfully I don't think they can truly guaranty things work but with the specified crystal they built their Rx's around.

I personally follow the rule of Hitec with Hitec, Futaba with Futaba, etc.

[Chris F]

Yea a chart would be awesome.

I personally follow the rule of Hitec with Hitec, Futaba with Futaba, etc.
Are you talking about receivers or crystals?

I have tried GWS DC Rx and Tx crystals and the throttle channel didn't seem to work. I swap the Corona DC receiver for a JR SC receiver and everything works. JR crystals seem to be a lot more compatible with GWS according to the GWS comparison chart at : http://www.gws.com.tw/english/product/receiver/crystal%20comparison%20chart.htm

This is why I bought SC GWS crystals to be used with my JR Tx crystal. I also bought a GWS Tx crystal to use with the GWS DC Rx crystals I bought because my JR Tx crystal wasn't compatible with any GWS DC crystals available.

My guess is that we are all guessing and we will get the best results either by trial and error, or someone who already knows the answers. I'm not going to try Futaba crystals yet, I will try JR crystals first as they are supposed to be a better match with the GWS ones I already have. I will also buy some Corona crystals when United Hobbies eventually get them in. I don't know about Futaba crystals, but I expect they are about the same price as the JR crystals; almost the price of a Corona Receiver :eek: I get this terrible feeling I'm about to get ripped off :confused:

And no, I don't expect that Hitec, Futaba etc manufacture their own crystals, but maybe they do.

[XJet]

I have tried GWS DC Rx and Tx crystals and the throttle channel didn't seem to work. I swap the Corona DC receiver for a JR SC receiver and everything works.

Your problem is unlikely to be the crystal -- if the other channels are working then the throttle should work too.

I suspect you've hit a firmware problem that was highlighted in the 72MHz version of the Corona receivers that meant they would not arm some speed controllers when used with a JR transmitter.

The only fix for this is to try another speed controller or get an updated receiver witht he newer firmware.

[Chris F]

Thanks XJet,

That sounds like a good explanation. I'll try another esc next time.

[Guz]

Are you talking about receivers or crystals?


I mean putting a Hitec crystal in a Hitech Rx, Futaba crystal in Futabe Rx, etc.

Xjet may have hit on the problem now that I think about it.