Youtube film

[Hugh Barnes]

Steve Wragg has been in touch this morning and mentioned a film on YouTube I had never seen before, a public information film about fitting suppressors to cars to prevent TV interference. A lovely 'period' piece but those of a nervous disposition may wish to look away at the end...

https://www.youtube.com/watch?v=DSSk-yonbDo

Hugh

[dickie65]

That reminds me of the fun father and I had in the 1970s running the 33 Box outside our house while the neighbour 3 doors down was watching the telly. I was fathers look out.
Every time the neighbour went to the telly to tune it I would signal father to cut the engine, TV Fixed !!! once the chap sat down again work on the Austin engine would proceed until the chap got up to re tune the telly.
This was good Saturday afternoon entertainment. !! especially on cup final day !!
I still have a few of the Acorn Suppressors in the garage.

[Reckless Rat]

Is this still relevant in the days of cable or satellite TV? My RP is fully unsuppressed.

[Parazine]

Is this still relevant in the days of cable or satellite TV? My RP is fully unsuppressed.

Nope, digital signals have some error correcting capability built in so the frames can be reconstructed if they're damaged. Also, cable is unaffected as it's broadcast along a wire and satellite uses different frequencies that are largely immune. If using Freeview over UHF, you might still see drop-outs if the signal is weak and interference is present.

[John Cornforth]

Yes - still very relevant

Unsuppressed ignition radiates mostly over the VHF and UHF ranges, so terrestrial analogue and digital radio and TV broadcasts are affected, along with professional and amateur radio communications. You won't see white spots and hear clicks and buzzes with digital radio and TV, instead you get "freeze frames" and stuttering.

In the UK, suppression was a legal requirement for new cars from some time in the fifties, but the law wasn't retrospective.

However, I suspect if you go to your local radio and TV shop these days (If you can find one), you won't get a polite and knowledgeable lady who sounds like the Queen !

[John Mason]

‘I believe you can still buy the inline suppressors for fitting to copper wire leads (not carbon I believe the carbon acts as the suppressor).

John Mason.

[Peter Naulls]

My father must have seen the film in the 1950s!

   

[John Mason]

If you had a car radio fitted you also needed to suppress the dynamo with a capacitor and sometimes the wiper motor if the car was fitted with electric wipers. On rare occasions the car radio had to be wrapped in aluminium foil and earthed to get good reception without the continuous noises from other electrical stuff on the car.

John Mason.

[Bob Culver]

Digital meters also do not handle ignition hash. For old car use a basic (1000 ohms per volt) analogue meter is more useful. Calibrate using much more accurate digital.

[Parazine]

Unsuppressed ignition radiates mostly over the VHF and UHF ranges, so terrestrial analogue and digital radio and TV broadcasts are affected, along with professional and amateur radio communications.  You won't see white spots and hear clicks and buzzes with digital radio and TV, instead you get "freeze frames" and stuttering.

Interesting. Our caravan, which we use for many A7 events has a digital Freeview over UHF connection and we do suffer from dropped frames and audio problems in weak signal areas. But these disturbances are not co-incident with the movement of the (largely unsuppressed) A7's about the site but more to do with people movements and movements of motor vans, cars and caravans, causing reflections and shadows in the line-of-sight signal. That old film was made at the time that TV was transmitted on Band I VHF (BBC only, no ITV until 1955), which was possibly more susceptible to interference from spark gaps?