Home Aerial distribution Band Plan 405 to DVB-T

[chriswood1900]

Following a major building project I’m now planning to use the extra Coax and CAT 6 cables put in for distribution of Radio and TV around the house.to achieve an environment to cover both modern technology and my older TVs and Radios. I want to have everything from Band 1 405-line TV, FM Radio, DAB radio 625-line Analogue TV Digital TV plus extra modulators to redistribute the CCTV, Sky and a music channel.

To achieve this, I have drawn up a plan of channels to fit it all in.
As this is the first time I have done this I would like some guidance on any errors I have made in the channel planning. I live in the Sutton Coldfield are and have an excellent signal with external aerials for UHF TV, DAB, FM and a GPS(for timing).

I will use a Hedghog for 405 line TV on Band 1, a Multiview T35 to regenerate the 5 625 line TV channels with Teletext and an FM modulator (still to sort) for my own FM music station. Local HDMI inputs will use 2 Technomate TM RF HD DVB-T modulators.
FM, DAB and Freeview will be passed through the system as is with any level adjustment required.
The aerial distribution will be with a Labgear LDU608R ( I will have to check its abilities on Band 1 as there is no published info)
I’m not distributing AM signals I will handle those locally for the limited number of old radios I have converting FM/DAB to AM.

I have attached a PDF of the band plan. Hopefully if have got it right it may be some help to others.
Thank you in anticipation of some feedback.
Mods if this is in the wrong place please move or delete.

[winston_1]

Interesting. Watch out for harmonics from the Hedgehog which could cause interference at higher frequencies. A low pass filter may be required.
I don’t think the Labgear is suitable as I doubt it will pass band 1. And why on earth do you need the satellite distribution it offers.

I have a home distribution system which has TV in band 1, 3, UHF, and a few frequencies in between but no radio. I use an old Antiference wide band distribution amp 48 to 860 MHz with 6 outputs each of which can feed two points via a splitter. Problem is amplifiers with band 1 pass are very difficult to source these days.

Combining is done before the amplifier either by looping through modulators or with splitters in reverse. Most modulators have sufficient output to allow this.

Good luck with your project.

[Graham G3ZVT]

Wow, what can I say?

The bandplan is crying out for a second 405 channel in Band III.
How else are you going to exercise those turret tuners?
Lichfield was on CH8.
& why is your BBC on London's frequency and not CH4 "Birmingham" as SC was called?

[Vintage Engr]

Just make sure that there's adequate cable screening, no cheap co-ax, -otherwise I might be able to receive extra channels up here on my isolated hilltop in Shropshire!
Can I have Band III as well, it will keep the contacts on the tuner biscuits clean!...

Good luck with the project. I was going to do something similar here, but although I have most of the kit required, I just don't have enough time at present.

David.

[winston_1]

Originally Posted by Vintage Engr

Can I have Band III as well, it will keep the contacts on the tuner biscuits clean!...

Yes, but do ensure you avoid local DAB frequencies.

[arjoll]

If you can track down a DA from another region it might be an idea - the one we installed 23 years ago when we built the house covers around 40-800 MHz as band I channels 1 and 3 were used off Hedgehope for PAL B until 2013. We did need to add a 700 MHz low pass filter when LTE band 28 was enabled though.

Is the really the kind of FM raster you guys work with though? It seems all over the place with seemingly random spacings. Here each major site is on an 800 MHz raster (for example Hedgehope is 89.2, 90.0, 90.8...106.0) with "infill" sites further out (which in reality get used for fortuitous coverage of Invercargill - our trust kind of started that with Life FM Mid Dome) 400 MHz off from that. I've attached a list of stations which either officially or unofficially target Invercargill.

Does the UK raster just highlight something that's grown organically and never been organised? You see similar 0.8 MHz spacings with some 0.4 MHz fortuitous coverage in pretty much every part of New Zealand, so our distance from other countries can't be the only reason this all seems more sorted here.

[chriswood1900]

Apologies for the slow response but I have very been busy finishing making changes to the heating and ventilating system.

How else are you going to exercise those turret tuners?
All of my 405 line TVs except the Sony 9-90 are single channel and the prewar one is Channel 1 only so that is why I chose that.

Just make sure that there's adequate cable screening, no cheap co-ax, -otherwise I might be able to receive extra channels up here on my isolated hilltop in Shropshire!
I have used good quality double screened cable throughout so I’m not expecting any problems, and I will check to make sure radiations are at a minimum.

Yes, but do ensure you avoid local DAB frequencies.
Yes I should be OK on that score as CH8 is around 189 Mhz so well below any local DAB frequencies I may use that if CH1 has a problem passing through the aerial amp.

If you can track down a DA from another region it might be an idea - the one we installed 23 years ago when we built the house covers around 40-800 MHz as band I channels 1 and 3 were used off Hedgehope for PAL B until 2013. We did need to add a 700 MHz low pass filter when LTE band 28 was enabled though.
I didn’t have any luck finding a suitable distribution amp so ended up buying new, it should be fine with Cellular signals as it has built in filtering for that.

Is the really the kind of FM raster you guys work with though? It seems all over the place with seemingly random spacings. Here each major site is on an 800 MHz raster (for example Hedgehope is 89.2, 90.0, 90.8...106.0) …
Yes those spacings are from the from the published list

Does the UK raster just highlight something that's grown organically and never been organised?
Probably yes.

I hope to be installing this later this week so will post an update soon!

[colourking]

Originally Posted by chriswood1900

Is the really the kind of FM raster you guys work with though? It seems all over the place with seemingly random spacings. Here each major site is on an 800 MHz raster (for example Hedgehope is 89.2, 90.0, 90.8...106.0) …
Yes those spacings are from the from the published list

Does the UK raster just highlight something that's grown organically and never been organised?
Probably yes.

the 5 national FM networks do follow a pattern (at the majority of transmission sites)

Taking the frequency of the lowest national network - BBC Radio2 , add 2.2, add 4.4 , add 9.6, add 11.8 (the latter network , Classic FM is much more likely to have exceptions, or smallers sites not used) to get the frequencies of the other networks.
National FM Frequencies in the Republic of Ireland were rearranged to follow the same pattern in the 1980s for 3 networks then (2 more networks opened later).

[chriswood1900]

A quick update
I have been a bit delayed with both a vacation and landscaping work at home so here is what I found so far.
Setting up the aerial amplifier has been straight forward and adding the 2 DVB modulators are working well.
The aerial amp does not pass signals in band 1 so the idea of distributing that from the Aurora has proved problematic so I have decided to just do that locally in my workshop. I had a new set of problems with the Multi view T35, on its own it works just fine but when in close proximity to the aerial amp and the modulators the 625 line signals are heavily modulated and full of interference. I have temporarily abandoned this solution and again moved it to the workshop where locally it works fine. The interference is not obvious harmonics but seem more related to the multiple oscillators in close physical proximity sorting this will have to be a winter project.

[G6Tanuki]

Many of the cheap modulators you can get for VHF/UHF TV are distinctly spectrally impure, if you try to cascade them and then feed them into a distribution amplifier the mixing products can be horrible!!

You need directional couplers and helical filters to stop the output of one modulator going back into the output port of the others and mixing - remember that even an unpowered bipolar transistor in an output stage has a varactor effect if you push RF up its output port...

It multiplies! It mixes! And all while seemingly powered off!! Power it up and it does all these, with added gain!!

I came across this sort of craziness in my mobile radio days: half a dozen transmitters sharing a tower would generate a mess of mixing products when the output of a couple got back into an inactive transmitter - you have potentially the same mess but in miniature. Directional couplers and helical filters to the rescue.

Good ones providing decent isolation are not cheap!

[m0cemdave]

The same thing occurs with radio microphones in close proximity.
There are various computer programs and spreadsheets available to calculate intermod-free channels when planning frequency allocations. You may be able to find one online.