Reftec 459 megs

[Former Member]

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[Former Member]

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[Myron Beaumont]

Phil

Trouble is -You might have to take his tent and gaz stove off him as part of a deal & probably Mr Ashby's  whatsit ! Its the first decent thing he;s mentioned but he won't swap it even though he doesn't want it .Oh well -I wonder what useless relics he's found in the "clear out " No wonder there's not a lot of activity on the swap thread ---Eric's put folks off !! I know its rememberance day BUT !  

[Former Member]

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[Phil Claridge]

ah but will you or the show still be aroud in fifty years time lol

[Former Member]

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[Peter Christy]

I bought one of the "MK2" Reftecs just after they went bust. Avicraft seemed to have bought up all the bankrupt stock, and I bought one cheap to see if they were as bad as reputed! The answer was a resounding "yes"!

 There were so many design flaws, that its difficult to know where to start!

At the time, everyone ws still using 27 MHz. The first IF of the Reftec double conversion receiver was - 27MHz!!! This would have probably been OK if they'd put the receiver in a metal case - but they didn;t! It was plastic! So everytime it got anywhere near a 27MHz set (like doing a low pass, or carrying the model out to the runway) the receiver went beserk!

 Then there was the crummy soldering, with parts actually falling out of the boards when shaken hard! (I had a coil fall out of the receiver board in flight!)

Still, at least the "MK2s" had some filtering on the Tx output! The original Mk1s had no filtering at all! When I looked at one on a spectrum analyzer whilst repairing it, it went right of the 'scope at both ends, completely filling not only the 459 MHz band, but a goodly chunk of spectrum either side as well! Just as well few clubs had more than one set! If ever a Tx deserved a "black pennant", it was a Mk1 Reftec!

 However, it proved a worthwhile purchase, as I knew what mistakes NOT to make when I designed my own 459 MHz system a few years later! My original prototype is still flying 20 years on in my old "Lark" helicopter.....

The best place for a Reftec? In a display cabinet, NEVER to be switched on!

 --

Pete

[Former Member]

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[Peter Christy]

Hi Eric,

Sorry - don't mean to offend - but my experience with Reftec gear was far from unique! About two years ago I gave the receiver to an old boy who wanted one for a boat - probably about the only safe place to use it, I reckon!

The problem was that the reputation of 459 MHz suffered enormously as a result. The Cotswold was a superb system, as was the Multiplex (still have mine) and modesty forbids me from extolling the virtues of my own

I also had the dubious pleasure of doing some tests on a Reftec 934 MHz CB radio (remember them?). It was an another appalling design susceptible to any tiny fluctuations in supply voltage, and horrendously unstable.

But the Mk1 Reftecs took the biscuit! There appeared to be NO FILTERING at all of the pulse train, resulting in enormous sideband splatter, and there was certainly no filtering of the RF stages, with the Tranny aerial being directly connected to the output transistor!!!

 The receiver used a single crystal to provide both local oscillator frequencies, with the result that the IF varied depending what channel you were on! The only way this could possibly work was by using an extremely sloppy (wide-band) receiver - so that's what they did! I wonder if they ever attempted to fly two on adjacent channels? It would certainly have been fun to watch!

I remember a car racing friend buying one and wondering about the poor reliability. When we opened up the receiver, we could actually slide the transistors throught the globs of solder on the board with our fingers! A good shake, and out they fell! Cold Joints? We've heard of 'em!!!!

I had to resolder every joint in my receiver to make it airworthy. On its first flight it shed a coil in the oscillator circuit - luckily the model crashed into a bush without sustaining much damage, or I might never have discovered the cause!

So I'm afraid I have to disagree with you on this one. No doubt a few escaped that were serviceable, but it was a poor design, and for the most part, badly assembled as well!

Now, does anyone know where I can get hold of a Space Control, or a RCS Tetraplex???

 --

Pete

[Former Member]

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[Peter Christy]

Well, I still make my own 459 MHz gear, but only for my own use now. Mick Wilshere manufactured them for a while, and they were very popular with the vintage crowd. I still get them back occasionally for service - usually just duff cells in the Nicads!

 Winter Hill! That brings back some memories! I spent a very nice summer working at the Holme Moss transmitter back in the early 70s, and we used to pass service messages on to Winter Hill most days!

Which brings me to another thought! Back then I was flying a Simprop Digi 5 - another dog of an outfit that gave me no end of grief! In fact the only place it ever worked reliably was on the soaring site at the end of the Holme Moss driveway! About 200 yards from a 100KW TV transmitter, three 10 KW VHF radio transmitters and two 1 KW local radio transmitters, and it worked like a charm! Anywhere else, and you never knew if it would get off the ground before it ran out of range!

Perhaps that's why you've never had any problems! The local TV transmitter must have constantly been kicking it back into life!!!!

 Its an ill wind..........!!!

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Pete 

[Former Member]

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