Mine Goes Up To 8!
 

A question for the heavy iron jocks from a humble Saratoga driver:

I recently bought a 747 transponder control head on eBay as a toy for the kids (see link below). The funny thing (to me, at least) is that it allows digits from 0 to 8 to be selected for what I assume is each digit of the beacon code. Since transponder codes are in octal and ought to go from 0 to 7, what is going on here?

http://cgi.ebay.com/ebaymotors/ws/eB...m=230199151135

You've been had? :}

One guess: They used off-the-shelves parts which allowed more numbers than a transponder needs? Are you able to select the eight or is it physically inhibited?

Dani

Here's the answer from a very kind soul at Gables...

> The G1884 series started in 1965. I started in this business in
> 1967. I don't know the whole story but back then ACT control
> panels allowed all 8's to be selected. Something to do with a
> "remote keyer" function. Apparently this function was never
> adopted and later revisions to product and newer part numbers
> only allowed 0 thru 7 selections on each digit.

So there you have it! 8888 presumably put the code under remote control from some other piece of equipment.

XPDR with "8" in digits...?
 

Don't get frustrated...
Same thing here...
xxx
I have flown airplanes with VHF COMM heads that could dial 117.xx -
And some others that could dial 136.xx as well, on the high end...
Yet the VHF COMM frequency spectrum goes from 118.0 to 135.999 mHz...
HF COMM heads that dial 2,000 to 29,999 kHz...
So, get confused with your XPDR...
Never say "it does not exist"... it very well might...!
xxx
:)
Happy contrails

Which is just as well really otherwise you wouldn't be able to tune frequecies of 136.xx for example Redhill ATIS or Gatwick ATIS 136.52 or indeed our company frequency of 136.xx

If you dial up 8888 you will start laying 'chemtrails' - not a lot of people know that.