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My Feedback: (7)

After sending several request to hitec for info, I'll for a last instance try this approach. I have a hitec Micro 555 receiver, ( RCD 8200) for which I need a crystal in Ch. 52. Where can I get one?

Any help would be appreciated

Thank you

A.T.

Hobbyhorse, being the first in list of several on quick internet search, has Ch52 in stock. Select "Hitec", "Channel 52", "Dual Conversion", "FM" > add to cart...

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

buchtes

My Feedback: (7)

ok A.T., I've done what you suggested, installed a HITEC PN 6677251 72 MHz Dual Conv. Receiver X-Tal Crystal which Hobby Horse send me. I still do not have a signal from the TX. Do to the age of the RX, ( about 10-12 years) I do not think it's worth spending more $ to get it fixed.
Or what else can I check?
thanks

A.T.

Without knowing both brand and model of the transmitter you are using, one would only be guessing and suggesting numerous possibilities e.g. is your TX set to QPCM, PCM or PPM - it must be set to PPM. If a Hitec computerised TX, it should be set to eithet "P" or "N" shift according to type of that 555 which is not shift selectable on 72 MHz. Suggest refer to:
Hitec RCD General Receiver FAQ
see also sub section "Glitches & Jitter in RX & Servo - causes and cures" at
Alan's Hobby, Model & RC FAQ Web Links
(FWIW Those were excellent RX, am still using a couple in large .EP Soarers.)
Regards
Alan T.

buchtes

My Feedback: (7)

TX FUTABA ; T 6 EXA is the TX, thank you.

A.T.

Futaba 6EXA (Manual). Early models were FM (PPM) modulation only whereas later versions were capable of both PCM or PPM. TX must be on PPM to operate the Micro 555.
The 555 is available in three different configurations. The 28272 (negative shift) is for Futaba and Hitec transmitters when using Futaba servos or older Hitec servos supplied with a "J" style plug.
The 28572 (negative shift) is for Hitec and Futaba transmitters when using Hitec 'S' servos (or "J" plugs amended by either snapping off the tab on recent servos or amending the old plugs to suit.)
The 28672 (positive shift) is for Airtronics and JR transmitters and will not operate correctly with your TX.
NB: Make sure the servos are plugged in correctly, looking at the top of the receiver, starting from left to right, it is signal, positive and negative (black lead closest to edge of case).
Micro 555 FAQ was to have been placed above the General Receiver FAQ on previous post, oversight is regretted.
Regards
Alan T.
Alan's Hobby, Model & RC FAQ Web Links

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My Feedback: (7)

thanks A.T., I guess I'll just retire the old RX, it's on the Blink. It is a 28272 neg. Shift, even has "FUT" printed on it. The TX is a newer Model, but I cannot know is it on PCM or PPM. I'll just go with a new RX and be less worried. Thank you anyhow

A.T.

If later 6EXA, PPM or PCM will show in tiny letters on top right of screen after TX is turned on.
1. Access the Model Select function in the programming mode (by pressing the MODE and SELECT keys simultaneously and holding them down for one second). Use the DATA INPUT lever to select the model memory you wish to modulation select.
2. Push SELECT key twice after seeing on the screen the model memory where you want to set modulation, then you will see “PULS” on the screen.
3. To select PCM modulation, push the DATA INPUT lever up. The “PCM” is displayed. To select PPM modulation, push the DATA INPUT lever down. The “PPM” is displayed.
4. To get the transmitter to operate in the new mode, switch transmitter power off and then on. The small indicator will indicate the mode, either PPM or PCM.
If above does not resolve your problem with Micro 555, then your new Hitec Dual Conversion crystal will work well in either of:
Neutron 6S
Supreme IIS
Regards
Alan T.
Alan's Hobby, Model & RC FAQ Web Links

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My Feedback: (7)

thanks Bud, I'll try that today.
Best Regards
David