Radio Question

[jure george]

Hello

I would like to ask members here, would a Futaba 6EXAP PCM1024 and the futaba R168DF receiver. Modified to 75Mhz FM, if Possible by Radio South, work for R.C submarine use, without issues?

I have a chance at buying one for a really good price in 72Mhz range.

Please let me know and if there are any issues.

Thanks
George

[vasily]

You better check with Radio South (by phone) to determine if they can convert the transmitter and receiver to 75mHz, and the cost for both. This radio does not appear to be have a plug in "transmitter module", which may be necessary for a conversion to 75.
You should also check the age and condition of the batteries- if they have to be replaced that will also add some cost.
Does it come with servos you can use?
Do you need fancy mixing, like differential steering / rudder?

You mention it's a good deal- I've purchased several Futaba 9C 1024 PPM/PCM sets from eBay and had them converted for less than $150.

[jure george]

Hi vasily


Thanks for your reply. I think I have a Good deal for the: radio, rec., main battery, rec. battery, A/C charger. No servos. ALL I need to know if Radio South can convert it to 75Mhz and how much and is it a Good radio for R.C sub use. The seller is asking $40.00 Canadian for the above listed stuff.
George

[JWLaRue]

If I recall correctly, some of the missing pulse detectors do not work with PCM-based systems. They require PPM. The 6EXAP can operate in either mode, however I do not know if the R168DF receiver works in PPM mode. So worse case, you may need to buy a different receiver.

That aside, the 6EXAP looks like it should work fine.

-Jeff

[jure george]

Hello Mr. JWLaRue

Thanks for your help. So IF I understand you, the r16DF Dual Conversion "Might" not work and I would have to buy another. Firstly the radio says it can be switched from PCM to PPM so would not i`t original r168df rec. work on both modes? I don`t know, just asking. IF it is not good, what other rec. should I look for?

Thanks Again
George

[Guest]

I used PCM on my first sub. It wasn't recommended back then, but I found it worked great. Third party failsafes become redundant with PCM, as it has failsafes built in already, but you do need to program to suit the model. The only other snag is the failsafes tend to react immediately upon loss of signal, whereas failsafes designed for subs tend to delay for at least a second or two so the odd glitch doesn't throw out your trim. In practice I only ever had my PCM failsafes kick in once, and that was on an occasion when I unwittingly found out I was sailing in salt water!

Modern PPM receivers with pulse conditioning made PCM a bit redundant, but if you have it available I wouldn't be too quick to dismiss it.

[jure george]

Hello
Thank You sub culture for your reply.

So if I get this radio, in which Mode should I run it in; PCM or PPM?

Thanks
George

[Guest]

For use with the receiver you have specified, you would run the transmitter in PPM mode, because the receiver is a dual conversion PPM receiver. You will require a dual conversion crystal in the receiver too, you cannot use standard single conversion crystals in them. the transmitter however does use standard single conversion crystals.

[jure george]

Hello sub culture

So if I understood you from your post#8. The transmitter will work on a standard single freq. TX crystal BUT for the rec. to work it has to have a Dual conversion crystal in the same freq. / channel as the single in the TX. Is that correct?

George

[Guest]

That's correct.

[jure george]

Thank You Again sub culture you have been very helpful. As well as the others here.

George