Futaba Tx question

[jbenini]

Greetings all, I'm starting to get back into the hobby after leaving in 1977. The plan is to do some scale electric experimentation with model hovercrafts (I'm a high school teacher and I build full size versions with my students) What I have at the moment is a Futaba FP-4NBL AM 4-ch transmitter, a GWS CE (motor controller?) a GWR-4N reciever, a Ni-cad battery pack and 2 GWS servos. I beleive the reciever is FM and the Tx is AM. What can I do to make everything compatible? I'm guessing the reciever will have to be replaced with an AM version, and I'll need a new battery pack and charger for both for the Tx and the hover. The Tx shows low battery when I turn it on, so my guess it's still working. I read that the 72mhz band was really for planes not gound vehicles, but I'm not planning on "flying" the models anywhere except at school. OK, what does everybody think is my best (and least costly) plan of action? Thanks! JB

[stevecooper]

Your gonna need a FM transmiter (TX for short) and your crystals are going to have to match as well ,,thats the bad news,,The Good news is that most RC flyers are useing 2.4 TX's now and used or free TX's are everywhere,,If you were closer I would fix you up with a used one,
Hovercraft kinda fly so FM 72mhz should be Cool,,I've had a kids RC club for 14 years and have the best times working with them,,good luck, let us know if you need anything,bubsteve

[pmullen503]

Ebay, your local RC club, or an RC swap meet are places to find, older used equipment. Someone on this forum may have what you need.

It may be easier and cheaper to get an entire system (tested and working) with matching frequency crystals than to try to find parts.

There are also very inexpensive 2.4 Ghz systems available new that you can buy.

[jbenini]

OK, so here's my next dumb question: if I'm going to replace the Tx I have with one compatible with the reciever, what do you suggest? I'll need 3 channels, 4 would be fine too, but I'm not sure what brand/model will work with the reciever I have. (Remember, I've been out of this sport for a looooong time and I need to learn about all the changes ) What do you guys think? Thanks again, JB

[Rodneh]

Using 72MHz for ground based vehicles is against the law, not a good example for a teacher to do an illegal act. You will most probably, in the long run, save money by just going ahead and going with a newer 2.4GHz system. By the time you buy a battery (you will need to for the old set if you want any reliability), match transmitter to receiver (both either AM or both FM) you will have spent about as much as you will have to for the less expensive versions of the 2.4GHz units. In fact, if you check with the local RC clubs, you may find a deal on a less elaborate 2.4GHz unit as many of the flyers are now updating their equipment and selling their older rather cheap.

[fmw]

There are some inexpensive import 2.4 spread spectrum transmitters available. It might be cheaper and certainly easier to pick one of those up. It would have the advantage of never having to deal with interference. Check out Hobby king. Go to the transmitter section. I think they have transmitters starting around $35.

[fmw]

Here you go.

http://www.hobbyking.com/hobbyking/s...x_Mode_2_.html

$29 and you can buy a receiver with it for about $8.50.

[jbenini]

OK, it looks good, reasonable price , looks like I'll still need to buy a battery pack, wonder if the GWS servos and speed controller will work with it? Maybe I should call the company and ask! I very much appreciate the help, I feel like a fish out of water looking at all the technologial improvements that have been made over the last 35 years!JB

[Wildflyer]

If your equipment dates from 1977, there is very little chance it is on a legal freq.

We finalized a change to new channels in 1988, I think there was a 5 year overlap. You would be far better off to ditch the old stuff and get new equipment.

Is your ESC from 1977? if so then it is for a brushed motor, if you want much more power at the same weight or less, you should think of going to brushless motors and brushless speed controls.

Sorry about your old system not being very usable. My father and I had 12 systems that went illegal in 1988. so it really bit us.

[jbenini]

I should have explained better: I've been out of the hobby since 1977, but the equipments is not from the '70's, it's newer than that. It's just that the Tx and Rx are different brands, different frequencies; I'm just trying to figure out if I can salvage and use any of it, or is it too old, too incompatible, too expensive to use, etc. JB

[NFA Fabrication]

6 Channel for $23: http://www.hobbyking.com/hobbyking/s...2_Mode_2_.html

They have a 4 channel as well, but it's the same price, so why bother!

[stevecooper]

Originally Posted by jbenini

I should have explained better: I've been out of the hobby since 1977, but the equipments is not from the '70's, it's newer than that. It's just that the Tx and Rx are different brands, different frequencies; I'm just trying to figure out if I can salvage and use any of it, or is it too old, too incompatible, too expensive to use, etc. JB

Post a Pixs of the stuff and we'll have a look!,, bubsteve

[Glacier Girl]

My 2 cents. Why try and build a late model Ferrari out of Model A parts? What you will spend making it work, time and dollars, will outweigh what it would cost to get current components.

Do as suggested, go 2.4 and brushless motors/esc's, and servos.


Your tx is AM not FM, about one of the most interference prone frequencies out there. Also the tx is as basic as it gets. No programming capabilty, something you will need for a hovercraft.

[hayofstacks]

A late model ferrari and a model t probably have more in common then most cars. You should have said volkswagon and porshce, although, they basically are the same cars...

My question, what makes it illegal to use for ground, and how would they be breaking the law? In auto shop we ran an engine on a stand without cats. You could argue its illegal to remove them, but only if you were to drive it on a public street. Growing up 72mhz was common on kids toys that were on the ground. I hope noone fires up an old toy without going to jail.

You can order a 72mhz receiver and crystal just about anywhere. $11 for the receiver and a couple bucks for a crystal. You can get a spektrum knock off 2.4ghz receiver for $11-13, but need to spend .round $100 on a dx5 newer radio, or a used dx6. Most of the hobby kind 2.4ghz systems for under $50 I would still consider to be more or less a toy. I would eel much better and think it would be safer to use an "outdated" 72mhz system.

[Rodneh]

The FCC has a list of the way you can legally use the frequency spectrum. In the USA, 72MHz is allocated for airborne models only and 75MHz for ground based vehicles. 6 meters (50 and 53MHz) are legal for both airborne and ground vehicles as is 2.4GHz in the USA. Different countries have different rules and regulations. For the most part, these rules are universal to prevent problems with commercial radio stations and communications between commercial jobs such as aviation concerns etc. Power limits are also stated in their specifications and varies by use and frequency.

[NFA Fabrication]

Originally Posted by hayofstacks

A late model ferrari and a model t probably have more in common then most cars. You should have said volkswagon and porshce, although, they basically are the same cars...

My question, what makes it illegal to use for ground, and how would they be breaking the law? In auto shop we ran an engine on a stand without cats. You could argue its illegal to remove them, but only if you were to drive it on a public street. Growing up 72mhz was common on kids toys that were on the ground. I hope noone fires up an old toy without going to jail.

You can order a 72mhz receiver and crystal just about anywhere. $11 for the receiver and a couple bucks for a crystal. You can get a spektrum knock off 2.4ghz receiver for $11-13, but need to spend .round $100 on a dx5 newer radio, or a used dx6. Most of the hobby kind 2.4ghz systems for under $50 I would still consider to be more or less a toy. I would eel much better and think it would be safer to use an "outdated" 72mhz system.

I don't even know where to start...

[jbenini]

Wow, I really didn't mean to open up a can of worms! I've been thinking, it might be better to forget about that Futaba tx and focus on finding a Tx that works with the system I have. I tried to call GWS, but both numbers I had went to places other than GWS. I thought they could tell me what Tx's they make that would be compatible with the Rx I have. It all came out of a GWS deHavilland Beaver model (actually it's still installed) missing the battery pack, but has the motor and reduction gearing. Anybody out there know for sure what will work with a GWS GWR-4N reciever? Thanks, JB

[stevecooper]

Originally Posted by jbenini

Wow, I really didn't mean to open up a can of worms! I've been thinking, it might be better to forget about that Futaba tx and focus on finding a Tx that works with the system I have. I tried to call GWS, but both numbers I had went to places other than GWS. I thought they could tell me what Tx's they make that would be compatible with the Rx I have. It all came out of a GWS deHavilland Beaver model (actually it's still installed) missing the battery pack, but has the motor and reduction gearing. Anybody out there know for sure what will work with a GWS GWR-4N reciever? Thanks, JB

Theres also Pos and Neg shift FM RX's,,, Futabas Neg,,, JR and airtoronics is Pos shift,,, yours is a Neg shift RX (GWR-4N) the "N" stands for Neg Shift,so Yes that is the right RX,,I hoped this helped,,bubsteve

[NFA Fabrication]

Originally Posted by jbenini

Wow, I really didn't mean to open up a can of worms! I've been thinking, it might be better to forget about that Futaba tx and focus on finding a Tx that works with the system I have. I tried to call GWS, but both numbers I had went to places other than GWS. I thought they could tell me what Tx's they make that would be compatible with the Rx I have. It all came out of a GWS deHavilland Beaver model (actually it's still installed) missing the battery pack, but has the motor and reduction gearing. Anybody out there know for sure what will work with a GWS GWR-4N reciever? Thanks, JB

What do you have against just spending $25 on a complete modern 2.4 system (Controller and receiver)? It seems like you've already used up more than $25 worth of time on this.

[jbenini]

OK, thanks for all the input guys! I bought a GWS transmitter that matches the reciever and servos I have. I got batteries today to put together a battery pack. So my next question is: does anybody out there have a pair of GWS Beaver wings they want to sell? I got the plane as a fusalage and motoer/partial radio set up (free) GWS no longer sells parts for the plane, I'm thinking it would be fun to put it back in flyable shape and fly at the local park. Let me know, thanks. JB

[Beemerider]

I've gotten back in the hobby with a 20 yr old radio. A narrow band 72 mhz Futaba. New batteries for $6, electric motor for $11, esc given to me, and $18 for a pair of Li-po's. The sailplane I already had and I've had fun putting it all together. I've got less than $40 invested (plus what I already had from 20 yrs ago). The stuff I just bought came from China but so far seems fine. It seems to me you can get into this neat hobby for a minimum investment.

[dahawk]

Originally Posted by Beemerider

I've gotten back in the hobby with a 20 yr old radio. A narrow band 72 mhz Futaba. New batteries for $6, electric motor for $11, esc given to me, and $18 for a pair of Li-po's. The sailplane I already had and I've had fun putting it all together. I've got less than $40 invested (plus what I already had from 20 yrs ago). The stuff I just bought came from China but so far seems fine. It seems to me you can get into this neat hobby for a minimum investment.

Beemerider,

You absolutely can do this on the cheap. But what I found was, once the addiction takes hold, you're wanting for more. More models: faster, higher performing, cooler looking, whatever.

I built several pusher jet(prop in the slot) foamie airframes out of Dollar Tree foam using free plans. So, one-two dollars for the air frame. 9g Servos from HK for ~$3.00 each. Knock-off Futaba RX for ~ $20.00, Grayson motor and ESC combo's for about $40.00. Lipo's for ~ $10.00 It's the little things and trips to the LHS that start adding up. Little parts and accessories like CF, horns, clevices, rods,velco, glue, tape,etc. Fun to do in the winter build season plus you learn everything there is to know about the plane.
What starts out for $2.00, quickly turns into ~ $100.00 once you're done.An airplane you built that actually flies? Priceless !

But you can buy a very nice ARF in this price range. The good news is that when I crash one of my scratchbuilts( happens) , I can recycle all of the parts and debris for the next cheap airframe. After a while, the costs start coming down.

The big hurdle is the TX and secondly, a decent battery charger. These are one time investments that are amortized over the entire squadron.

My two cents...

Hawk

[Beemerider]

Hawk--
I wholeheartedly agree! I spend a couple hours each evening scouring ebay and other hobby sites looking for stuff I can't live without. I've bought the iMax B6 charger, extra props, servo tester, battery tester, and now looking to buy a wattmeter (which I should have bought instead of the battery tester--but no biggie--none of it's very expensive)

This hobby took hold of me 20 yrs ago and in no time I had near a dozen glo engines including 4 stroke. Several radio systems, 6 planes and the list goes on. It doesn't take long.

It's fun and keeps an old fart off the streets.


Wayne

[AEAJR]

Just a comment about old equipment. It is old. Things corode, frequencies shift and parts are hard to come by.

Today's RC equipment is so cheap, why mess with old radios, receivers and old servos. The probability of failure is high.

As noted above, a new 2.4 GHz radio system can be very inexpensive and they work quite well. No more frequency control issues, no more crystals.

Give some thought to whether you really want to use that old stuff.

I wouldn't.