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All posts by Chris.SE

Below are all of Chris.SE's postings, with the most recent are at the bottom of the page.


nick:

If you are feeling like experimenting, then certainly a log periodic would be worth trying as it will have less sidelobes and rejection from the rear is better, beamwidth is also generally narrower. There's quite a few appearing now in recent times, so they are getting more popular.
There's a bit of tropo around at present (BBC & Freeview have warnings) and certainly last weekend ish during some of the hot weather continental reception was coming in on parts of the east coast.

As you undoubtedly know, LPs will have a flatter response over the band which could give a bit more gain on the lower channels but less at the top depending on what you choose and compared to what you currently have.
With your previous experimenting etc., you'd know what sort of gain you have with your current setup and therefore what sort of LP to choose. There's quite a few "K" group LPs around now as well (Blake are making some, as well as others). "K" group is the "new" wideband now that COM7 has gone, there's nothing above C48 (except Mobile as and when it appears!).

Whilst wideband ones are still available, I get the impression that stocks of same are "winding down" in favour of K group, unless you have a filter (or can get a free one from restoretv.uk because there's a new mobile mast near you), K group is worth considering to help being a bit more future-proof from possible mobile interference.

Search carefully as there are many which are quite sensibly priced, there are a number where rip-off prices are being charged for things which aren't special. It depends on what sort you want to go for and where you buy from!

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jp1:

I don't think you understand. If there is no Local multiplex transmitting in a particular area, or you are too far from a transmitter that has one, using a different postcode won't make the slightest bit of difference, reception will be unchanged.
This is not satellite where sometimes different postcodes can affect the region received.

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It's worth pointing out that the original post with the query about LCN 51 was back on 15th January and all LCNs above 23 (excluding 24) got renumbered up one on 26th January to accommodate BBC Three on LCN23.

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Ted Slater:

Unfortunately there is no way of sharing pictures here. In the past people have uploaded to a site where a link can be provided, or found a picture of something identical and given the link to that. I've found this one which sounds almost identical, Part Number 27884D4 -
https://www.philex.com/products/product/slx-4g-48-element-digital-tv-aerial/

If you click on the image it shows an enlarged picture.
This user guide for the "kit" version, I don't know how similar yours was -
https://pdg.cef.co.uk/downloads/pdg/philex_27884k4_a_datasheet/philex_27884k4_a_datasheet.pdf

Are you able to see how the connections are actually connected to the dipole, nuts and bolts or rivets etc.?
What is the loop resistance to the aerial measured from the connection that would go to the splitter?

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Ted Slater:

Frustration is probably an understatement.
As the aerial has a balun, I'm glad there's no loop resistance, at least no short circuits!
With only a 2m length of cable, I would guess it's pretty obvious to check that it's not been crushed at any time which could affect its performance.

Now, in such circumstances, one has to question the (not so?) obvious. As you've checked the cable from the splitter to the TV and done those other measurements, one is left with suspicions about the aerial (especially as we both I guess, are out of other ideas).

Lofts are subject to extremes of temperature and at times there could also be condensation. Different metals in contact with one another can also have reactions over long periods of time.
So although the connections may "look" ok, I'd be inclined to unscrew everything that can be - including the dipole to balun. Make sure everything is spotlessly clean, very carefully use meths to clean contact areas only, maybe use a cotton bud, don't want to upset any varnish!
When re-assembling pay special attention to the braid clamping screws making contact with the PCB and the braid with the PCB if there is copper under it.

I really can't think of anything else at present, this has to be a really odd one.

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Ted Slater:

Hmm, always interesting to see what else you can get.

Now, one question I haven't asked, because of your background I expect subconsciously I might have expected you to have mentioned it if it were so, but are there any new (or changed) mobile phone masts near you?
I'm wondering if there's a strong enough signal, is it getting into your system between the TV and or at the Distribution amp? If so, might it desensitise the TV tuner especially at the top end?
How easy would it be to try the filter at the back of the TV with the aerial coupled direct to the downlead (amp off)?

More straw clutching - is there an unused VHF input on the distribution amp? If so, try a shorted plug on the input, who knows what interference may get in there!

As you have a distribution amp, do you have maybe a small(er) TV on a different downlead/output that you could compare strengths/quality between C48 and the other channels? No need for exact figures, just comparisons, nor exact comparisons with the main TV.

If you have a smaller TV, how easy would it be to take it to the loft and connect direct to the aerial (no amp) and try a channel comparison and if need be also with the filter. If not practical could you have such set at the bottom of the loft stairs and have a separate length of coax from the aerial coax to the set?

This could be all straw clutching, but might eliminate any obscure possibilities!

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Ted Slater:

Trying my suggestions will eliminate certain things and prove others without any shadow of doubt!
Sometimes what appears to be obvious turns out not to be :(

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Ted Slater:

Recent conversation here on the Nottingham page is on p53. Some links are opening on p7 !!!

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C
GREAT! movies action | free and easy
Saturday 30 July 2022 1:31PM

David Bowley:

This is not their website and they are very unlikely to see your comment here.
For contact information, see https://www.greatnetwork.com/contact-us/

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Dougie Blackwood:

Apart from the fact that current weather conditions might periodically be causing some disruption to reception, it's never a good idea to retune if you have low signal quality or large errors, it can result in clearing your correct tuning and possibly tuning to incorrect channels from more distant transmitters receivable because of the weather.

There are currently no listed faults for the Roseneath transmitter that I can find and it doesn't appear to be listed for Planned Engineering.

That said, you mention the correct UHF channels, but not C45 which is the PSB3/BBCB HD multiplex, so am I correct in thinking you don't get the HD channels on 101-105 etc. (your sets don't have a T2/HD tuner) ?

You say you can see the mast but how far away is it?
Are your aerial rods (or squashed Xs) horizontal or vertical?
How old (roughly) is the aerial?
Was the coax from the aerial replaced at the same time as the aerial?
You presumably have a splitter if feeding more than one TV, is it just a passive splitter or an amp/splitter, if the latter, how old?

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