TOPIC:

Hi there,
all if my Holiday Buggies are/will be ready to run although they will only see the show case for rest if their life.
When I buy old cars for restoration sometimes radio is installed but no transmitter comes along with the buggy. So I need to purchase transmitters from 1980 to get the run. But if I look international it is not easy to get them in the same frequency band (27,40,72Mhz).

Here my question. If you have an old AM transmitter like the old Tamiya/Acoms is the freqency only given be the used crystal? So if would take the transmitter that you can use 27Mhz crystals als also 40 or 72? Or are the transmitters internally fixed to the range and you can only change the band?

Harry

RLine wrote:

Hi there,
all if my Holiday Buggies are/will be ready to run although they will only see the show case for rest if their life.
When I buy old cars for restoration sometimes radio is installed but no transmitter comes along with the buggy. So I need to purchase transmitters from 1980 to get the run. But if I look international it is not easy to get them in the same frequency band (27,40,72Mhz).

Here my question. If you have an old AM transmitter like the old Tamiya/Acoms is the freqency only given be the used crystal? So if would take the transmitter that you can use 27Mhz crystals als also 40 or 72? Or are the transmitters internally fixed to the range and you can only change the band?

Harry

Definitely the latter - only 27mhz range crystals work in 27mhz transmitters & so on. You can use different brands though.



But ... do you really need 1:1 correspondance between transmitters & cars? A smaller range or period transmitters might make a better display ... I'd want a Mk.1 & Mk.2 Acoms + a futaba Medallion 2 at least, plus maybe a (blue painted metal metal brand that escapes me for the moment) & a couple of earlier Futabas, I'm not up on the model numbers but there's a "sand" coloured painted metal TX, a steerwheel one of the same vintage/look, and another fairly conventional 2-stick TX but with the antenna coming from one side rather than the middle.

I think the early Futaba series was called the “ M series “.
So the Sandy coloured set.

The twin stick set was quite a big thing.

In France they were different bands. 26, and 41 mhz. But accept 27 and 40 mhz crystals.

Both the transmitter and receiver need to be the same system, i.e 27, 40 et and both AM or FM.
The crystals need to match this and notice transmitter and receiver use dedicated crystals, marked TX for transmitter and RX for receiver.

But within you choice of system, you can use whatever band you want as long as it's legal in your country.
In my country its legal to use 26.995-27.995 in the 27mHz systems.

It is getting harder to buy crystals from stores now, so if you can buy a bulk of different crystals, do it.
The stores that still carry crystals have narrow selection of crystals and they are getting more expensive by the year.
I know my LHS just have a few in stock, no pairs and I was only able to match one set from their stock.

Thanks for your feedback. That´s too bad that I cannot just switch the crystals...
My concrete topic is a radio set shown in the picture. I putchased the Buggy from Beldium. According to the crystal it is a 7eMhz System. Couldn´t find anything about the original company. But obviously also came from Belgium at that time (Space Systems Belgium). But the type of the receiver KR-V2 and its appearance seems similar to the K.O. Digiace V2.
I tested the set by using a 40Mhz Crystal and my Futaba AM transmitter. It worked so far, but the servos are not travelling that far as they should do. I would guess 50% of the typical travel way in both directions.
I assumed to root causes: The crystal switch is not working of the 0-100% signal from a Futaba is different to the one from Digiace (or Space Systems).

I really would like to get the system running, so I have not that many options:
- Buy a Space Systems 72Mhz Transmitter -> not very likely to have success with that
- Buy a K.O. Digiace 72 Transmitter -> also could not find any.
- Buy a K.O. Digiace 27Mhz or 40Mhz Transmitter and use 72Mhz crystal on the Transmitter or a 27 or 40Mhz crystal on the Receiver. -> that was my best option…..till today.

I hope we have Belgium members that can help you out.
As you say 72mHz is not common or so I thought. Seems Futaba has some of the stuff in the 72mhz system.
What I understand, the 72 system is really for the air, and should not be installed in a ground vehicle at all.

Europe tend to use 27 or 40 systems, america 70 and 40 if I remember correctly.

I think I would have bought a complete radio gear on ebay, with transmitter and receiver and then supply crystals if needed.

You can find on ebay some mk2 or mk3 acoms system. But mk3 is a little too young for the HB. Look for sanwa dash (without servo reverse system). Or anterior.

The goal is not just to get a working RC system. There are good sets from that time available from time to time in different configurations.
My goal is to get the one of the picture running or get the ones running which are pre-installed (if working or can be restored).
Harry

Sorry.