Worrying about their second harmonic ?

[FMEnjoyer]

All rather extreme.. if it is all true.

[radionortheast]

The first documentery I saw was about pirates in hackney, busting the bogs to put aerials up or something, theres the video anyway.
I think theres a bit more going on here than a few pirate radio transmitters, the focus of this is the radio aspect of it, not been told about other problems, were left to play dot to dot, it impossible to know what was going on, sounds like that dj was innocent.
I think they did various nights on bbc2, about lightening the other about radio, they go into detail about the smashed toilet, they get the bearing at the listening station, I don’t know if that was ballcock station, known as boulderdock or something but the other names funny.

[FMEnjoyer]

I will choose words with care given the heavies might have been involved.

"Ballcock" lolz, made me laugh Northeast i imagine you mean Baldock, in Herts. No idea north east I just liked the music I liked all the pirates then, rock, rave, oldies, Indie, bit of reggae. I suppose it was naive to think at some part of rave there were no heavies involved behind the scenes. What you don't know you don' worry about. Not the DJ's as you say, they earn a crust from their DJ sets in the clubs and raves.

The electrified bars if it was true, we can join the dots indeed, seems a bit more than just keeping the listeners ears filled with fresh rave hits 24/7.
Clearly the big majority of people were having a good time playing music and not involved in anything more.

I suppose some had more financial concerns in pirates hey day than others, some anoraks tech and music hobbiists, some a few ads to pay the raids and some much ore running as a business concern.

Someone on the comments asked why they did not cut the electric to the floor, that would have cut the TX.

[FMEnjoyer]

I wonder if Caketin FM at 07:20 was as bad as it looked, copper clad construction, VFO at aguess.
That was one shabby looking rig and power supply tied onto that plank.

[radionortheast]

"Ballcock" lolz, made me laugh Northeast i imagine you mean Baldock, in Herts. No idea north east I just liked the music I liked all the pirates then, rock, rave, oldies, Indie, bit of reggae. I suppose it was naive to think at some part of rave there were no heavies involved behind the scenes. What you don't know you don' worry about. Not the DJ's as you say, they earn a crust from their DJ sets in the clubs and raves.

Yeah I couldn’t think of the name of it, pirate radio was something that came from else were here, with them coming from miles away, there was no idea what so ever what went on them.

[Albert H]

Rigs bricked into walls, studios wherever they could be covert, some amazing technological advances (in the name of not getting found)..... That's what we were up to!

[radionortheast]

wasn’t it flava shine fm were they had to get the crane?, pretty made some crane drivers day. Maybe if stations were causing a pain to local residents they could get raided more often, thats what I always thought that and it overloading tvs, lots of djs coming to the studio could look like drug dealing. I suppose even if a signal is low power it still has no licence to be there, but will obviously be causing much less issues.

[FMEnjoyer]

Radio Floorboard 87.456 used to have a £4,000 spectrum analyser gaffer taped to the far end of the floorboard to ensure their second harmonic was 65db down on the main carrier.

[Persona Non Grata]

RE; The Army being brought in to bust pirates there was this SW pirate (Radio Merlin International -not to be confused with the onetime name of the crowd who run transmitters for the BBC world service) who used to transmit from a woodland adjacent to a motorway with electricity coming from a lamp post.

Anyways the story goes that a concerned member of the public was out walking their dog (or whatever it is concerned members of the public do on foot next to motorways) saw metal boxes and lengths of wire beside motorways and assuming the worst (this is back in the days when IRA terrorism was still a big thing) contacted the police who sent the army in to carry out a controlled explosion on the TX (they probably had the motorway closed as well although I can't remember)

[radionortheast]

Maybe they got haunted by it, think the 2nd usually falls above the ham band, the lowest you could get to would be the old radio microphone band, around 174, so haunting someones radio micophone with the 2nd harmonic.

[EFR]

Maybe they got haunted by it, think the 2nd usually falls above the ham band, the lowest you could get to would be the old radio microphone band, around 174, so haunting someones radio micophone with the 2nd harmonic.

Military air traffic starts from 220Mhz, highest 2nd harmonic is at 216Mhz, so safe about it.

[Albert H]

I know one station that deliberately linked on a harmonic of their output frequency, in an effort to conceal its existance. As long as the filtering on the main rig was really good, it worked well. As I recall, they used a crude cavity filter on the link receiver input!

[radionortheast]

Military air traffic starts from 220Mhz, highest 2nd harmonic is at 216Mhz, so safe about it.

In the uk a transmitter in the upper part of the fm band the harmonic would fall in the dab radio band.

I know one station that deliberately linked on a harmonic of their output frequency, in an effort to conceal its existance. As long as the filtering on the main rig was really good, it worked well. As I recall, they used a crude cavity filter on the link receiver input!

I wonder if that was what veronica super gold were doing I saw a picture with 220mhz frequency, later on they used the mains 455khz, I think they used dummy uhf at the same time. https://garrystevens.vze.com

[Albert H]

Back in the 80s, we used all sorts of methods. I linked one South London station from their flat-based studio to their rooftop (some floors above) using the Neutral and Earth of the building's mains wiring. Their link was on ~335kHz FM, and was stereo capable! The only tricky bit of the design was to ensure that there would be no damage if they connected to the mains Live. After a lot of thinking about it, my eventual "fix" was to fit a small 12V panel lamp in series with the Neutral lead, which would blow (very quickly) if it was ever wired up wrongly!

The circuit of the link RX was based (loosely) on the NE565 PLL datasheet circuit, and included carrier detect which allowed the presence or absence of the link signal to switch their main rig on and off. The link TX was a simple PLL circuit (to keep it on frequency) with a very slow loop filter (it took about 10 seconds to lock up) which allowed very wide deviation (compared to the carrier frequency). The receiver would lock reliably to the incoming signal, even though its oscillator was free-running.

They used this link system through several raids, and Gotts always removed their rig and the dummy link RX plugged into it, and cut their TX coax and the (pretend) link receive aerial lead. The link receive (TV) aerial provided a DC short, so I added a simple switching circuit to their main rig so that it would go off after a few seconds - credibly - if Gotts cut the "link" coax first! After the first raid, the rig that Gotts found was always a dummy, and he would remove a rivetted-shut cheap aluminium fire alarm box containing a brick and a 40 Watt lightbulb which would warm the heatsink nicely. Unplugging anything would kill the actual rig, and through the life of that station, Gotts only ever got one real rig!