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Stations that were linked over fm or relayed how was it done

Posted: Wed Dec 24, 2025 6:47 pm
by radionortheast
I remember hearing this was done, were a station had a little 0.5w, 1w, in the fm band that was linked to the main transmitter. I also saw this been done by someone in another country, they only had the main transmitter in a tree outside, suppose thats just how they frost themselves.

I think I remember reading the wakefield transmitter for dream was fed from the leeds tx on 107.8, seemed quite a close channel spacing to do that. When the relay was in York it was too far away to do this, they used a 15w link, some were outside of the fm band which really popped, was maybe to far for away for stereo. Relays didn’t happen up north, I don’t remember them happening other than that, I think there were some stations in London that had relays, wonder how it worked. I think broadcast receievers are expensive can’t see how they could be used, if you had a penthouse you could have one.

With licenced stations the whole feeding from another fm transmitter is rare, chance of it been interupted by a foreign station, maybe get lucky have bailando paradisio coming across all radio channels, they could get hijacked, like the southern tv hijacking. There was rumour if the feeds went down for a national station, they maybe had a back up, were they get them over fm the nearest transmitter, remember hearing something about there been a broadcast chain. That maybe the reason even those these frequencies could be used, they had to kept clear, maybe just rumour or rumour has it. :D

I suppose usually a uhf link would be directional, so perhaps would not beable to be picked up from two different locations, unless they were in the same direction, or of the phouse lol. Seems like the link is in horizontal mode which helps from overload from the ding dong, the main tx is in vertical…suppose makes it interesting is if they are both in vertical at close frequencies. I was thinking if there some were high up, they would likely receieve a good signal from the other transmitter but the receive aerial been in horizontal would away to combat it.

Re: Stations that were linked over fm or relayed how was it done

Posted: Wed Dec 24, 2025 8:40 pm
by EFR
I have done some linking on FM back in the day, just trow one cheap portable radio to the second transmitter site, listening main transmitter.

Second transmitter output has to be clean and about 1-2Mhz is enough between them.

Re: Stations that were linked over fm or relayed how was it done

Posted: Fri Dec 26, 2025 12:33 am
by Albert H
My very earliest links were done using a cheap broadcast tuner modified to go below Band II. We used about ½W on 82.2 MHz to link from our studio to the main transmitter site. The receiver board I used was one sold cheaply by "Henry's Radio" in London's Edgware Road. It had a "tuned" lamp output, which I used to drive a little relay, and turn on the supply to the main rig.

The transmitter fed a dipole in the loft above the studio, and the main site had a dipole in the roof of the garage that housed our main output medium Wave transmitter. The link system worked flawlessly for the two years that we ran from that site, and probably only cost about £10 to build at 1972 prices!

Re: Stations that were linked over fm or relayed how was it done

Posted: Fri Dec 26, 2025 3:25 pm
by shuffy
During the 80's & 90's there were 2 stations in the Stockport area which used links in, or near, the FM band. The first, in late 1984, used a 5W VFO rig on (approximately) 105.8MHz which at various times (although never simultaneously as per the original plan) was feeding a rig in the lower half of Band II on a high point 5 miles away from the studio, and an AM rig just under a mile away. The link receivers were car radios. Probably the highest quality receivers commonly available at the time. Back then the FM band didn't contain any broadcast stations above 105MHz so the link stuck out like a sore thumb and was easily audible on a normal FM radio over a fair chunk of south Manchester. Distribution of the signal was the main priority but obfuscation of the link wasn't really possible due to limited availability of specialist kit and test equipment. Miraculously, the studio itself wasn't raided.

The second one, about a decade later was just above the top of Band II around 110MHz between suburbs just over 2 miles apart. The RF parts were purpose built based on circuits culled from domestic receivers and a 10.7Mhz IF strip kit (ambit?) which could fire up the main rig via a relay. Antennas were, if memory serves, a dipole and a basic domestic 3 element FM Yagi both horizontally polarized. This station did get raided but not for linking in the air band specifically - he'd had a falling out with someone from another station and let's say things went downhill after that.

Both these arrangements worked OK with the main (Band II) rigs running between 50 and 100W in close proximity to the link RX and in the case of the 2nd station, albeit the weaker of the 2, less than 5MHz difference between the link and broadcast frequencies.