DAB Help & advice sought, please

[bmathieson]

I have recently moved to Plymouth from Scotland and I set up my DAB receiver in exactly the same way as before: I have a 3 element aerial in the loft space pointint in the same direction as all the tv aerials are pointing around here (towards the main transmitter at Saltash, I believe). I have it in horizontal position.

Here's the problem: I have used a UHF/VHF Antiference splitter to run the signal down a single cable before unsplitting it at a pair of sockets in my living room. This worked before, first of all with my FM aerial & radio years ago and more recently with my DAB aerial & radio in Scotland.

Currently, I am getting absolutely no signal from any station/group on DAB. Is the problem the position of the aerial or the use of the FM/UHF splitter, in which case, what should I be doing?

Your help would be appreciated.

 

[bmathieson]

I have recently moved to Plymouth from Scotland and I set up my DAB receiver in exactly the same way as before: I have a 3 element aerial in the loft space pointint in the same direction as all the tv aerials are pointing around here (towards the main transmitter at Saltash, I believe). I have it in horizontal position.

Here's the problem: I have used a UHF/VHF Antiference splitter to run the signal down a single cable before unsplitting it at a pair of sockets in my living room. This worked before, first of all with my FM aerial & radio years ago and more recently with my DAB aerial & radio in Scotland.

Currently, I am getting absolutely no signal from any station/group on DAB. Is the problem the position of the aerial or the use of the FM/UHF splitter, in which case, what should I be doing?

Your help would be appreciated.

 

[kenny1234]

Hi Brian welcome to the forum

Is the 3 element aerial in the loft actually a DAB aerial?

DAB aerials should be mounted vertically, if you are able to mount the aerial outside this will also help in receiving a stronger signal although it does look like there have been some recent issues with DAB transmissions in Plymouth see _http://www.digitalspy.co.uk/forums/showthread.php?p=37040961

 

[kenny1234]

Hi Brian welcome to the forum

Is the 3 element aerial in the loft actually a DAB aerial?

DAB aerials should be mounted vertically, if you are able to mount the aerial outside this will also help in receiving a stronger signal although it does look like there have been some recent issues with DAB transmissions in Plymouth see _http://www.digitalspy.co.uk/forums/showthread.php?p=37040961

 

[satelliteman]

Yes very much sounds like a 3 element FM aerial horizontally polarised.

Also make sure the UHF/VHF splitter/diplexer passes 174-230Mhz.

 

[satelliteman]

Yes very much sounds like a 3 element FM aerial horizontally polarised.

Also make sure the UHF/VHF splitter/diplexer passes 174-230Mhz.

 

[PaulR]

Also make sure the UHF/VHF splitter/diplexer passes 174-230Mhz.

A simple test would be plug the DAB receiver into the other outlet of the downstairs splitter and also removing it completely to test the downlead.

It might be a good idea to test the upper splitter by removing it temporarily and connecting the aerial directly to the downlead.

 

[PaulR]

Also make sure the UHF/VHF splitter/diplexer passes 174-230Mhz.

A simple test would be plug the DAB receiver into the other outlet of the downstairs splitter and also removing it completely to test the downlead.

It might be a good idea to test the upper splitter by removing it temporarily and connecting the aerial directly to the downlead.

 

[Channel Hopper]

Yes very much sounds like a 3 element FM aerial horizontally polarised.

Easiest way is by the width of the aerial. FM is approximately 1.1 metre upwards, DAB is 60cms upwards.

 

[Channel Hopper]

Yes very much sounds like a 3 element FM aerial horizontally polarised.

Easiest way is by the width of the aerial. FM is approximately 1.1 metre upwards, DAB is 60cms upwards.

 

[bmathieson]

Thanks for the responses to date. It's definitely a three element DAB aerial - about 60cm width. I've rotated it to vertical polarisation, but still no luck, despite getting adequate reception on 3 portable DAB radios in the house. It sounds like splitter issues. My next task is to try the aerial plugged directly into the tuner - I'll do that directly in the loft, in situ for the aerial.

If it's the splitter that's the problem, I see that Maplin have a UHF/VHF splitter and a three-way socket comprising Satellite, UHF and FM/DAB. Will replacing what I have with these help me any?

Cheers, folks.

 

[bmathieson]

Thanks for the responses to date. It's definitely a three element DAB aerial - about 60cm width. I've rotated it to vertical polarisation, but still no luck, despite getting adequate reception on 3 portable DAB radios in the house. It sounds like splitter issues. My next task is to try the aerial plugged directly into the tuner - I'll do that directly in the loft, in situ for the aerial.

If it's the splitter that's the problem, I see that Maplin have a UHF/VHF splitter and a three-way socket comprising Satellite, UHF and FM/DAB. Will replacing what I have with these help me any?

Cheers, folks.

 

[bmathieson]

I tried by-passing the splitter and got a perfectly good signal (now that I'm vertically polarised), so clearly the splitter - an Antiference UF21 - is the problem. It is intended to allow FM and UHF to combine in one down cable, so I guess DAB gets filtered out. What I need seems to be a splitter that combines DAB and UHF.

Any suggestions where I can get one?

 

[bmathieson]

I tried by-passing the splitter and got a perfectly good signal (now that I'm vertically polarised), so clearly the splitter - an Antiference UF21 - is the problem. It is intended to allow FM and UHF to combine in one down cable, so I guess DAB gets filtered out. What I need seems to be a splitter that combines DAB and UHF.

Any suggestions where I can get one?

 

[satelliteman]

As mentioned in post #3. You require a vhf/uhf diplexer covering a vhf of 88-240MHz.

 

[satelliteman]

As mentioned in post #3. You require a vhf/uhf diplexer covering a vhf of 88-240MHz.

 

[PaulR]

The splitter is most likely from pre DAB days when Band III, which is now used for DAB, was used for TV.

 

[PaulR]

The splitter is most likely from pre DAB days when Band III, which is now used for DAB, was used for TV.

 

[Channel Hopper]

I tried by-passing the splitter and got a perfectly good signal (now that I'm vertically polarised), so clearly the splitter - an Antiference UF21 - is the problem. It is intended to allow FM and UHF to combine in one down cable, so I guess DAB gets filtered out. What I need seems to be a splitter that combines DAB and UHF.

You could get away with using a modern triplexed socket in reverse (just ignore the satellite part), or if really courageous, a simple two way splitter as the strength and bandwidth of the signals received by the DAB antenna is highly unlikely to muck up the TV.

 

[Channel Hopper]

I tried by-passing the splitter and got a perfectly good signal (now that I'm vertically polarised), so clearly the splitter - an Antiference UF21 - is the problem. It is intended to allow FM and UHF to combine in one down cable, so I guess DAB gets filtered out. What I need seems to be a splitter that combines DAB and UHF.

You could get away with using a modern triplexed socket in reverse (just ignore the satellite part), or if really courageous, a simple two way splitter as the strength and bandwidth of the signals received by the DAB antenna is highly unlikely to muck up the TV.