A couple technical questions about radios & receivers

[Coelacanth]

I admit to being a bit technically out-of-touch when it comes to some specifics about radio & receiver equipment, but figured your answers to some questions would benefit me & others.

1) If I have Futaba Magnum transmitters & receivers in the 75 MHz range, can I install any crystal pairs in that range in the Tx/Rx units, or do I have to get Futaba crystals?

2) Will any Futaba Rx (for example) work with any Futaba Tx, provided it's in the same frequency range?

3) Will any servo work with any Rx/Tx, as long as the plug fits the Rx? For example, can I use a new Futaba S3003 servo with a Rx that originally used old S148/S48 servos?

4) What do you guys recommend for a rechargeable battery pack for the Tx standard 2 x 2 x 2 AA brick-style or newer 4 x 2 AA flat-pack style battery holders?

Hopefully you'll excuse any ignorance in my questions or terminology. Thanks!

[soniccj5]

I am running a new 2.4Ghz with old servos, so you should be able to run new servos with the old receiver.

I use standard rechargeable batteries for my radio.

ED

[Coelacanth]

That's what I'm using now too, ED...I just find it a pain to have to keep 8 separate batteries charged up when it would be simpler to connect a 9.6V pack to my battery charger. Thanks for the info on the servos.

[aconsola]

1. crystals are interchangeable between some, but not all makes. safest is to make sure they are made by or specifically state they work with futaba

2 the tx/rx has to be on the same frequency and band. 75mhz am will not work with 75mhz fm, but all futaba 75mhz am rx units should work with any futaba 75mhz am tx.

3. any servo should work with any rx. the only restriction is you cannot use non-digital servos with certain high end modern systems.

4. use whichever one physically fits your radio, or just put loose nimh aa'a into the stock batt holder.

[aconsola]

That's what I'm using now too, ED...I just find it a pain to have to keep 8 separate batteries charged up when it would be simpler to connect a 9.6V pack to my battery charger. Thanks for the info on the servos.

I use a 3s lipo pack in my futaba 3pk, much lighter than the nimh, and lasts significantly longer between charges.

[Coelacanth]

Great info, aconsola, thanks! Anyone else, feel free to add your own advice.

[noony]

I have a lot of Futaba crystals if you need any!

[wyldbill]

i have had good luck with energizer E-square lithium aa's. their voltage is 1.7-1.8 volts and they lasted me like 2 racing seasons in my 3pj

[drbelleville]

1) If I have Futaba Magnum transmitters & receivers in the 75 MHz range, can I install any crystal pairs in that range in the Tx/Rx units, or do I have to get Futaba crystals?

Which Magnum Radios do you have (examp. FP-3 PB, 2-PD etc)

[floodx]

Second the lithiums - they last forever in a transmitter

[Coelacanth]

1) If I have Futaba Magnum transmitters & receivers in the 75 MHz range, can I install any crystal pairs in that range in the Tx/Rx units, or do I have to get Futaba crystals?

Which Magnum Radios do you have (examp. FP-3 PB, 2-PD etc)

My trusty original T2PK, 2 recently acquired T2PKA's and a T2PH (thanks treehugger!). I love those old T2PK/T2PKA's, they look great, feel right, they don't look cheaply constructed like many newer models (even compared to the T2PH), and function reliably.

Check out the X-Acto engraving on Old Faithful, totally forgot I did that back in the day!

Couple things I'm missing: 1 battery cover for the T2PKA and the T2PH; battery holders for both T2PKA's; and 2 antennae for the T2PKA's. If you got any spare parts lying around, by all means let me know.

[drbelleville]

I had a couple of those radios in storage, let me see if I have any left that I could easily give to you for parts. Those radios are great, and if you find an older Novak or Tekin receiver to go with them even better. They are perfect for a build where you are not worried about ABS, EPA, etc. I have an old Futaba Magnum 2PD for an old RC12L that my niece runs every time she visits - just right.

If I remember correctly the antennas are the same throughout various models. You can call Futaba Customer Support and they might be able to help out some (although they can be a bit rough around the edges).

[Coelacanth]

If I remember correctly the antennas are the same throughout various models. You can call Futaba Customer Support and they might be able to help out some (although they can be a bit rough around the edges).

There's at least one difference between the antenna used on the T2PK series and the one on the T2PH. The K antennae have a threaded hole at the base of the antenna (female) while the H has a threaded stud (male).

If you have the parts I'm missing, please let me know--and thanks for checking!

[losiXXXman]

I think you can use any AM with any other AM (same band of course). As for FM, Airtronics and JR can talk to each other, but not to Hitec and Futaba (who talk to each other).

[lpddpd]

So here's a question or two about receiver antennas. Is nitro fuel tubing a good enough insulator against carbon fiber? Does the antenna have to be fully extended straight or can I coil it under the body for a cleaner look? I'm talking old AM and FM 75Mhz not the new 2.4 Ghz stuff. I have a Kose on board antenna on an old car and started thinking about how that set up is and if I can duplicate that.