copyright (c) S.Bluck. 2004-2019


0 to 40 at 100mph. (2)
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One of my early safer-setups had two output transmitters, Both hidden, Located in two
blocks of flats and fed from the same studio via a mid-point-link.  They both used the 
closed-loop system for switching off the output transmitter and links. The studio was 
never raided and never lost a day due to equipment failure. just the odd hour or two,
Good fun to set-up and keep running. Stations like this were funded by drug money, so
the funds were made available to do things better. The studio had CCTV cameras looking 
at the approaches to the studio, checking out cars and people arriving and leaving.
These studio sites varied from a flat in a london tower-block, to a cozy discreet flat, 
Food arrived brought in rather than delivered. no excess noise from the studio. records 
were brought in and out in sports-bags, not record/CD cases. DJ's wore headphones. From
the outside it was just a normal flat. The rent got paid every month, all bills were paid.

On the output sites the aerials changed from time-to-time. Sometimes single or twin
di-poles, sometimes co-linears. and a couple of times I used simple quarter wave
whips on a flat steel plate. These couldn't even be seen from rooftop level. And
definately were totally invisible at ground level.  People argue that only a twin di-pole
or co-linear is good enough. BUT. I did not have a problem funding powerful transmitters
so I could (if needed). trade of antenna-gain for stealth. At both sites, the link RX was
located in a flat a few floors down from roof level. The signal path to the roof 
was FM vhf at a very low signal level up the TV distribution wiring, often to modified
UHF-VHF converters left there from the old 405 line television days. (TELENG SX panels etc).
The rooftop link receiver was plugged into these, giving the impression that the 
signals were being received using the block's own television aerials.
  

The signal path went like this:-

-Studio, 2x Microwave at 10GHz towards output sites, switchable with an A-B-Box.
-  -  -  OR  -  -  -
-Studio, 10GHz to mid-point, 2x Microwave at 10GHz towards output sites (tone switched)

-Output site, (rx in flat) 50MHz to 220MHz up to roof level.

-Output site, (rooftop) VHF rx to band II output transmitter with various trips.

-Studio, Band II receiver to monitor the output.


From the studio either button A or B was pressed to select one of the two
feeds from the studio or midpoint to the output site. Being a stereo station,
when the main transmitter fired-up the 19kHz pilot tone from the output TX
lit the stereo light on studio's monitor RX and this was used to keep the links
up. If for some reason the 19kHz disappeared due to kit-failure, or output site
raid / theft, The link chain switched off automatically. Then to fire-up the 
second transmitter you just pushed the other button and waited for the 19kHz
tone to come back, This time from the other output site!

As mentioned above, There were a few trips added to the output site and mid-point
repeater site to drop the main/link TX.  These were reed-switches on doorframes, 
PIR alarm-sensors and Light sensors hidden in some quite unexpected places. The 
idea was to not give the game away to anybody wanting to follow the link back 
towards the studio site. The transmitter would drop-out the link-chain would
drop, and Was then fired-up to the other output site while 'phone calls were 
made, and "our guys" would be at the output site to see who was responsible with
baseball bats, knives, or anything else!  (Zl nalguvat ryfr jnf n unaq nkr).

This setup was the exception rather than the rule. Most stations then and now
just can't cover the costs and complexity involved in this type of setup.

Pirate stations today haven't moved up very far on the staircase of technology.
More PLL controlled rigs, Many poorly made pieces or crap from china, and also
some very nice exciters and FET amps. Some stations use cables, or VHF/UHF links
and there are more microwave links than in the past, still too few brain-cells!

Just occasionally though you do get a sense of humour, Mostly on the non-FM
stations, where things are taken a tad less seriously. Where running the station
is still seen as a fun thing, and usually a prelude to an evening at the pub.

--

A few years have passed since I was seriously involved with the FM/Drug-Dealer 
pirate radio stations. But I do still have a few FM transmitters, Three good
commercially built transmitters and some home-built kit. two Mediumwave, And
six HF and SSB transmitters, some self-built and some commercial. 
So when the third world war happens, have a tune around and you'll hear me 
running them off my generator or wind turbine from a hilltop somewhere in Kent.

Most of my time is now spent designing electronic, radio and other projects and 
products Many of which use microcontrollers.  and of course   www.TORRadio.org

And for fun...?.....   Well!     It's All Fun,   or I wouldn't do it!
I have a few vintage vehicles. Motorbikes, landrovers, tractors, and a dumper truck!
And I shoot, re-load my own ammunition, and make my own black-powder too.
.
copyright(c) S.Bluck. 2005-2019