DSO Channel Duplication

Ezra Pound

Well-Known Member
I have read on other threads that people are getting duplicate TV channels stored in the ‘800’s’ and this is usually due to receiving signals from more than one transmitter, Sutton Coldfield recently had DSO stage 1 of 2 and I noticed duplicates of BBC4, Cbeebies and BBC Parl. In the 800’s, On further investigation I found ALL signals in my case are coming from Sutton Coldfield (and Lichfield = HD ) and the reason for the duplication is that these 3 channels are on MUXs ‘1’ AND ‘B’ Both from Sutton Coldfield
Yes. When we went though DSO, I had several duplicate channels before the DSO was fully completed. That was before I had an HDR though. My Topfield puts them in the 1000's not 800's..

It does sort itself out though...
I did a scan on my girlfriends new HD box last night in Manchester and it picked up duplicates from the Isle Of Man!
They must have some fairly strong signals lol

It looked impressive when it finished scanning and said found 186 channels though haha
It does sort itself out though...
I am not convinced that it does. After our last autotune the Humax had settled on a strange selection of multiplexes from different relays and some of the ones in the lower channel positions were of such low strength that they were unwatchable. A manual tune so that all multiplexes were received from the local relay (which is low power but in line of sight) fixed the problem. I think the tuning software is better on the HDR than the 9200 but is still some way from perfect.
I had presumed that Wallace was referring to the transmitter duplication sorting itself out (after DSO stage 2 of 2) rather than the Humax
Don't forget that the final stage of DSO on a transmitter usually includes a "power up" where the transmit power is often increased dramatically so those duplicates may be here to stay!

I now get duplicates from a distant transmitter on lower channel numbers than my local tx since the distant tx completed DSO.
The original post covered duplicates from a single transmitter, After DSO 2 of 2 the power (at Sutton Coldfield) will go up from 8KW/10KW to 200KW per MUX and at the same time most radio frequency channels will change, I suspect the programs carried within each MUX will also move around (removing duplicates) So you will only get duplicates from multiple transmitters. You should be able to get rid of the distant transmitter signals with a UHF attenuator