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Re: Acoms 2-channel stick radio evolution 12 years 4 months ago #4377

Rx aerial lengths - I recently read up on aerials etc whilst trying to build a better portable one for my TV. We know that the lead length is (Should be) important, but they say that aerial length should be a direct factor of the wavelength to work properly, usually half or quarter for convenience. If frequency = speed of light/wavelength, then surely all aerials should be the same length (Or a factor of it) for a given frequency? Makes you wonder if they've actually worked it out or just bunged a lump of wire on that looks right!


I think the properties and/or efficiencies of the components in the RX must play a significant part too, giving rise to the variation in length ... as a general rule I've noticed that "early" RX's like the ARA-227 and early Futaba models have very much longer antennas ... but overall there seems to be no concrete information about how long an antenna should be - so when people ask "my RX wire is borked, how long is it supposed to be?" I'm hoping we can have the answers.

On the other hand, maybe there is no right answer & antenna length "design" may be the engineering equivalent of "pin the tail on the donkey" :S

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Re: Acoms 2-channel stick radio evolution 12 years 4 months ago #4406

All a bit odd really... yes I noticed that early RX leads are much longer too. Perhaps if we measure a modern one & compare it with an early one, we'd find the early one is 2x the length of a modern one (Haven't looked) which would make sense. Basically, an aerial is tuned to 'ring' at a certain frequency - the same as a guitar string - if your string is a certain length & you twang it, you get a certain note, if you make the string half the length & twang it, you get the same note but at a different octave (Is that the right word? I'm not a musician). If you make the string a length that's not a factor of the original length (ie not 1/4 or 1/2 etc), you get a completely different note. All/any components that come after the aerial are just 'conditioning' the signal eg fine tuning it, boosting it, filtering out the bits you're interested in etc, but the basic aerial length determines what general frequency it's 'listening' to. Any old lump of wire will pick up the radio signal to some degree, (Just not efficiently) so maybe the manufacturers are trading off the expense of an extra tuning/boosting section in their RXs against the inconvenience of long antenna wires (Equivalent of a wah-wah pedal for said guitar - take the signal & modify it to suit your needs rather than just put the right signal in in the first place). I can't believe you're making me think about this, I'm gonna have to go & look at it properly now!

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AP 227 First Appearence 12 years 4 months ago #4529

Returning to the the initial posts and trying to narrow production dates down, I've finally hooked up my scanner and came across this interesting piece from February 1979 issue of Radio Control Models & Electronics magazine.

Assuming the February issue was in the shops during January and allowing for 3 months to go to print as was often the case and still is often today - then this places the date of the photo around November 1978. As yet I've not found anything earlier than this....

It's a single page review of a Graupner 1/12 Ferrari, the chassis picture clearly shows the Acoms ARA-227 receiver and ASA-227 servos installed + switch installed on the side of the chassis.

It appears to be a production item, also, the page numbers of RCM&E were continual throught the year, hence page 182 here.

The most eye opening piece I've found is from the RCM&E Model Cars Special from 1979 which has quite a bit of info on the first Acoms radio in a review of the XR311 & Cheetah.

I will add further pieces later & try and nail down release dates, when we get to the Techniplus / Technidrive era there's quite a few nuances. At least 3 different box designs for the MkIII and three receivers I think .... ARC-227, ARE-227 (BEC) and AR-227FE (I think) I received the ARC-227 with my Tamiya Fox April 1987 & the AR-227 FE with my Tamiya Monster Beetle Christmas 1988. The ARE-227 I think you have pictured above , but not listed in the receiver list, it must have been inbetween time.
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Last edit: by Peter Ellis. Reason: picture

Re: AP 227 First Appearence 12 years 4 months ago #4531

...Returning to the the initial posts and trying to narrow production dates down, I've finally hooked up my scanner and came across this interesting piece from February 1979 issue of Radio Control Models & Electronics magazine.

Assuming the February issue was in the shops during January and allowing for 3 months to go to print as was often the case and still is often today - then this places the date of the photo around November 1978. ...


Good stuff - I think that's pretty compelling evidence that puts the release date of the "mk.1" a whole year earlier than previously thought - which means a whole load more early cars are "appropriate" for the mk.1 - certainly as far back as the Toyota Celica LB Turbo (58009, release date 1st November 1978) & I will amend my first post accordingly :)

Earlier cars I'm not so sure about - in practice I think anything from the XR311 (58004) & maybe the Tyrell that preceeded it will probably have a mk.1 set in it - but mainly because they will have languished on a shelf until "cheap" 2-channel radios made them accesible (If it hasn't come across before - I'm very much of the belief that the dominance Tamiya had in the UK market was due in no small part to them being so often partnered with Acoms gear :) )

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Re: Acoms 2-channel stick radio evolution 12 years 3 months ago #4638

Finally got around to reading the 8-page RIKO (Richard Kohnstam Ltd, the UK importer for many years, and responsible for the dire "Mud Busters" video that appears as a bootleg {I assume} DVD now & then) "guide" to Acoms radio gear/chargers & batteries that came with one of my mk.1 sets ... it's remarkably free of auctual content, and devoid of any dates or figures ... the highlight really is the back cover, which shows an AP227 mk.1 TX, ARA-227 RX, an AWA-227 battery/switch set, and two servos ... without colour & because the labels are obscured you can't tell what model they are, but I believe they are ASA-227 servos, not the AS-1 ... which tells us nothing new :whistle:


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Last edit: by Jonny Retro.

Re: Acoms 2-channel stick radio evolution 12 years 3 months ago #4690

Added:


Mk V box pic
Mk V RX (AR227FE) & RX antenna length (449mm)
Mk V servos (AS-7)

AP201 (Alpha) box pic

:)

edit - I'd also like to know if anyone has got any information on antenna flags/ribbons - I know the mk1, 2 and 3 had them, I'm not sure after that ...

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Last edit: by Jonny Retro.

Re: Acoms 2-channel stick radio evolution 12 years 3 months ago #4695

I think the AP-227 Set manual is online elsewhere, re: Mudbusters, remember, this was back in 1991 way before DVD and there were no commercially available videos of Tamiya cars whatsoever - so back then it was pretty exciting ! I'm sure Riko only said "here's the cars, go make your film". The official Tamiya advertisements were more professional , true.

Back to topic, I will try and scan further info re Mk 1 to Mk V -

The AS-2 & AS3 servos were supplied with the 4 / 5 channel AP-427, AP-440, AP 472, AP435 sets - They feature a slightly different plug (the security clip is missing so they fit in the receiver as per later ones) The AS-3 has a green on silver label, There must be a difference between AS-2 & AS-3 , but I can see that for practicality, they had to have different plugs to get all the channels into the 4/5 channel receiver, was that the only difference?

The ARE-227 receiver comes between the ARC-227 & AR-227FE receivers - The ARD-227** was never produced but appears in the Fox advertisement it seems.

The AS-10 servo is listed in the Autumn 1989 Riko Spares booklet as a Mini servo....

scans to follow to narrow those dates down.....
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Beatties Advert for AP-227 June 1979 12 years 3 months ago #4697


From the June 1979 issue of Radio Control Models & Electronics magazine, a full page Beatties advert for the Acoms AP-227 set ! Also shown are the 6V Acoms battery & 6V mains charger & Quick Charger from 12V source. Opposite this page is a great Beatties advert for the Tamiya cars of the time RA1201 to RA1208 + 2 Tanks with Beatties own descriptions!

Elsewhere in the magazine an advert for Bob's Models of Birmingham has the AP-227 set priced at

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Last edit: by Peter Ellis.

Acoms Techniplus AP-227 MkIII - August 1985 12 years 3 months ago #4699



So far this is the earliest appearence/ mention of the AP-227 Mk III Techniplus set from August 1985 issue of Model Cars Monthly . It shows the set and also the internals of the receiver and servo !

The servos appear to be AS-5S servos , the photo's not too clear but I can see there's two digits after 'AS' so not AS-7 servos yet.....

Also shown later in the article is the 'Multiplex Delta' radio set, which must have been some arrangement with Acoms as the transmitter is identical to the Mk III and receiver may well be similar - the badge is different and it looks the same however the transmitter had an inbuilt charging circuit (charging jack somewhere) and the receiver had different style plugs on the flyleads...

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AP-227 in XR311 / Cheetah review June/July 1979 12 years 3 months ago #4700


An interesting and telling snippet from the 1979 Radio Control Models & Electronics Model Cars Special from June/July 1979. This is page 4 of the review which states they have run the cars for six months with the Acoms 2 channel set, having gone through 3 different sets from first prototypes to present production items, this puts the earliest sets at around October 1978.

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