Help Identify These Aerials

HappyHarry

Following on from a previous thread seeking Aerial recommendations for southwest Wexford...

This is the folks house and I have just been down there. There is a mess of equipment that was put up and fallen down over the years.

On the roof there is a pole that is about 8 ft above the highest point on the roof with 3 Aerials.

1) Old battered VHF antenna missing many parts including the dipole and no longer connected. I'll be removing that.
2) Some sort of Yagi X beam Horz Pol? Looks like it was pointed at Presley but cradle is broken. Is this worth fixing, or what should I replace with to get digital from Presley?
3) Grid Aerial, pointing out to Sea? Where is this getting it's signal?

Each aerial appears to have a Masthead Amp, some in very bad shape. One full of water and the others rusty inside.

In the loft there are 3 white boxes that I assume are the amp power supplies.

Due to bad weather and poor access I have not been able to trace the cables from each power supply to each aerial. however by trial and error I have unplugged two of the power supplies and still have decent reception of the 4 Irish stations.

I assume that this reception is comming through the grid antenna, but don't know where from. Any ideas?

The grid aerial is probably presely.
It looks like it was put up there to replace the knackered group B

The vhf aerial is horizontal and looks like an old Blaenplyf welsh VHF array.
I'm wondering why they put that back up as it looks like the pole is about the same age as the grid whereas the vhf aerial would have to be at least 30 years old if not more.

HappyHarry

Thanks for the reply.

Deleted User wrote: »

The grid aerial is probably presely.
It looks like it was put up there to replace the knackered group B

Could be, although it wasn't picking up any Uk channels in mid August (i know analogue is off now), but that could be due to the very dodgy masthead amp or bad alignment I guess.

In my brief research I learned that these grid type antennas are low gain, so would it be much use for Presley?

What is recieving the Irish stations? It it possible that the Group B lying on the tiles is picking anything up?

Deleted User wrote: »

The vhf aerial is horizontal and looks like an old Blaenplyf welsh VHF array.
I'm wondering why they put that back up as it looks like the pole is about the same age as the grid whereas the vhf aerial would have to be at least 30 years old if not more.

The VHF was put up by dad about 18 years ago. Possibly for radio? He was more interested into getting BBC Radio than TV. Infact I don't think there was a TV in the house when that went up. I'm pretty sure that is the original pole but the pole may have been replaced a few years later, it is high grade stainless steel so doesn't show it's age.

The other antenna's are both less than 10 years old.

I'll do some more investigations next time I'm there in a week or two. The aim is to get rid of the stuff that's not any use any more including aerials, cables, and power supplies. And then try to get UK Digital, with a eye on Irish digital for next year.

Can you recommend a suitable make and model of high gain group B for Uk digital?
Something robust and rust proof with a decent masthead amp.

HappyHarry

...659.jpg was full of rain water, I assume this doesn't work anymore.
What is it? With 3 wires, i am guessing some sort of combiner?

...661.jpg is the inside of ...660.jpg
looks in pretty bad nick, any idea what it is?

Well I assume that ..664.jpg is a Masthead amp, really what i want to know is can I \ should I do anything about the corrosion?

lucernarian

What should be done about that corrosion is.... Replace the masthead amp in use for the grid. Everything else is banjaxed. The aerial could be broken too, I can't tell with all the white stuff (salt??). Clean up around the screw terminals of the grid aerial and see what nick they're in.

If you want, you can then re-make the connections by connecting the central core to the existing terminal before, and some uncorroded shielding braid to the other terminal screw/bolt. A location like that really really needs some waterproofing/rustproofing. Silicone grease is great stuff for that. NOT silicone sealant for bathrooms etc. Get some of that grease off the net, and apply liberally over the connections and around the rubber gland where the cable actually enters the aerial balun (black connection box in centre of aerial)

3 wires means it's a combiner/splitter. If it mentions Ch21-35/37-68 or VHF/UHF it's a combiner. Otherwise it's a splitter to serve two TV outputs inside the house.

It's probably a good idea to get back to us with some idea of where each cable goes, as I doubt that grid aerial alone would give good reception of the 4 Irish ones. Though your location wouldn't have great reception of Preseli I think...

SW wexford yet on the coast? Where exactly?
I'd say presely would be ok there if it's all sea track...though the hill in SW wales thats between waterford and presely mentioned in the other thread may come into play.

I only looked at the last of those attachments by the way.
That box is definitely banjaxed

Incidently 4 of the 5 analogues from presely are still on the air untill sept 16th with five on ch37 being the strongest so you can still look for them.
I'd imagine your aerial is not functioning and needs a good service.

lucernarian

Deleted User wrote: »

SW wexford yet on the coast? Where exactly?
I'd say presely would be ok there if it's all sea track...though the hill in SW wales thats between waterford and presely mentioned in the other thread may come into play.

Just what I was thinking. I couldn't call up any good terrain maps of Pembrokeshire. What I found did suggest that there was poor terrain due west of Preseli, but Waterford and SW Wexford would be WNW of Preseli. Well there's no harm in fixing up the aerial that's there. A wideband, shielded masthead amp can be used for a different transmitter/RTE tx if Preseli doesn't work.

HappyHarry

Deleted User wrote: »

I only looked at the last of those attachments by the way.
That box is definitely banjaxed

Ha! Have a look at the second one!;)

HappyHarry

To_be_confirmed wrote: »

It's probably a good idea to get back to us with some idea of where each cable goes, as I doubt that grid aerial alone would give good reception of the 4 Irish ones. Though your location wouldn't have great reception of Preseli I think...

Thanks for the replies. I hope to get down there in the next week or so and have a good look, remove the none working stuff and trace the cables inside the house.

Sounds like everything on the roof is in knackered

Still puzzles me what is bringing the 4 irish channels in. Maybe there is another aerial in the attic.... it wouldn't surrpise me!

The irish channels especially the uhf ones would come in anyway in a half reception sort of way.
Here a paired length of co ax brings them in!

Presely is very very good in Rosslare so if you are due west of there ,even 20 or 30 miles,you are good to go.
I doubt the hill we mentioned that affects waterford will harm your reception.

HappyHarry

Deleted User wrote: »

Presely is very very good in Rosslare so if you are due west of there ,even 20 or 30 miles,you are good to go.
I doubt the hill we mentioned that affects waterford will harm your reception.

Yup about 20 miles west of Rosslare, near Fethard on the coast.

Reception is quite good on all Irish chanels and did get very bad when unplugging all amp power supplies.

St Senan

I would say that those aerials were getting channels from the transmitter in Dunmore east
thats where the majority of houses in the south west of the County got English channels from.

HappyHarry

scaller wrote: »

I would say that those aerials were getting channels from the transmitter in Dunmore east
thats where the majority of houses in the south west of the County got English channels from.

Neither the Group B or the grid were pointed in the Dunmore direction.
they would both be kind of in the direction of Presley but look to be a bit too far south.

What can you tell me about the Dunmore transmitter? Does it supply the Irish stations too? Is it UHF, what polarisation?

If I have the channel numbers on the TV for the 4 Irish stations can I figure out where they are coming from? Is there a list of channel numbers for various transmitters somewhere?

St Senan

I can pm you some details of an Aerial rigger down that way if you want

HappyHarry

scaller wrote: »

I can pm you some details of an Aerial rigger down that way if you want

Sure that would be great although I'm leaning towards the DIY route, with the purpose of learning a bit more about the whole thing.

St Senan

pm sent

Gadgie

HappyHarry wrote: »

What can you tell me about the Dunmore transmitter? Does it supply the Irish stations too? Is it UHF, what polarisation?

If I have the channel numbers on the TV for the 4 Irish stations can I figure out where they are coming from? Is there a list of channel numbers for various transmitters somewhere?

The Dunmore transmitter is UHF and vertically polarised. It only supplies the main four UK terrestrials. Channel numbers are 48 - BBC2, 55 - ITV1, 65 - BBC1 and 69 - Channel 4. Channels are fed from Sky digiboxes and are all 4:3.

Frequencies for RTÉ main transmitters and relays are available at http://www.rtenl.ie/downloads/television-frequencies.pdf.

HappyHarry

Gadgie wrote: »

Frequencies for RTÉ main transmitters and relays are available at http://www.rtenl.ie/downloads/television-frequencies.pdf.

Thanks for that.
From memory it looks like TV3 and TG4 from Mount Leinster.
RTE1 and RTE2 from Mount Leinster LP relay.

Make sense?

Mount Leinster Main Transmitter and Mount Leinster LP Relay are both Group A Horz pol would I be right in assuming that a single antenna pointed in the same direction will pick them both up?
I guess as DTT is on Group B, there is no point in buying a Group A aerial so it should be Wideband?

Antenna

Gadgie wrote: »

The Dunmore transmitter is UHF and vertically polarised. It only supplies the main four UK terrestrials. Channel numbers are 48 - BBC2, 55 - ITV1, 65 - BBC1 and 69 - Channel 4.

What was on 55 and 65 from that 'deflector' were forced to move to new channels AFAIK,

as the Dungarvan RTE transmitter was testing DTT MUX on 55 (though that later moved to a better channel - 62) and AFAIK still has a blank DTT test signal on Ch 65

Gadgie

Antenna wrote: »

What was on 55 and 65 from that 'deflector' were forced to move to new channels AFAIK,

You're probably right. I noted those frequencies down about a year ago when I was staying at my parents' house and haven't checked since. I did notice BBC1 was gone when I was down there the other day, but the UHF antenna is pointing at Mount Leinster and only picks up poor reception from the deflector so I didn't think anything of it.

HappyHarry wrote: »

Thanks for that.
From memory it looks like TV3 and TG4 from Mount Leinster.
RTE1 and RTE2 from Mount Leinster LP relay.

Make sense?

Mount Leinster Main Transmitter and Mount Leinster LP Relay are both Group A Horz pol would I be right in assuming that a single antenna pointed in the same direction will pick them both up?

What does LP stand for - Low Power? My parents' house in Dunmore East has VHF and UHF aerials pointed at Mount Leinster but they don't pick up RTÉ 1 or 2 on UHF from there (or if they do, it's not watchable). Picture on TV3 and TG4 is perfect. Maybe you'll have better luck in Wexford.

HappyHarry

Gadgie wrote: »

What does LP stand for - Low Power? My parents' house in Dunmore East has VHF and UHF aerials pointed at Mount Leinster but they don't pick up RTÉ 1 or 2 on UHF from there (or if they do, it's not watchable). Picture on TV3 and TG4 is perfect. Maybe you'll have better luck in Wexford.

I don't know what LP stands for, but perhaps you are correct and it is a secondary low power TX at the same site. I found it listed on the RTE NL document linked to earlier in this thread.
It's 100W with RTE1 on 29, RTE2 on 33 i think from memory that is what we were getting them on. I will check next week.

Antenna

THE UHF RTE1 and 2 is only for an area very close to the mountain under the main beam, where I assume the main VHF transmission has multipath (reflections/ ghosting) problem

oldbat

Great pictures.

The biggest problems you have are the usual seaside wind, rain and salty corrosion. You need to keep all this stuff out of the electronics and secure all the bits well.

Whatever else you do, get self amalgamating tape and good quality PVC tape, not cheap stuff.

Use satellite type cable throughout or at the very least between the aerial and amps and combiners. If you can, get masthead amps which are sealed metal boxes with F connectors. They are rust proof. The connections should be covered entirely in self amalgamating tape to about an inch and a half down the cable. The plastic case should be held shut with at least 5 turns of PVC tape in two places no matter what other locking mechanism there is. Then, when mounted on the mast, put some more turns of PVC tape around the box and the pole to hold it in place.

Remember what the wind and rain are like in winter, you want this to last as long as possible.

If you have to use the Fringe Electronics red type that you have, use self amalgamating tape around the grommet to an inch and a half down the cable. You may have to push it in with your fingers as you go. The plastic thing that holds it to the pole tends to break after a while unless supported so at least 10 turns of PVC tape around it and the pole will help keep it in place and keep the lid shut.

Same for any diplexers, combiners, etc.

Put all of these on the opposite side of the pole to the prevailing wind or main winter storm direction to shelter them. This also protects the cables.

Use at least 4-5 turns of PVC tape every foot to keep all the cables secure.

Where the cable enters the box on the aerial dipole, use the rubber boot if supplied then cover the whole area with a couple of inches of self amalgamating tape.

You can do all that anywhere but it is essential if you are by the sea, otherwise you end up with the corroded mess shown in your pictures.

oldbat

Did you check what frequencies the FM aerial was used on? Then you could be sure what transmitter it was pointing at. Preseli seems very likely. I have recieved perfect stereo 100 miles from a main transmitter using a 5 element FM aerial and VHF amp just like the ones in the picture. Vertically polarized VHF signals propogate better so if the polarity is mixed at the transmitter, changing the aerial to vertical often improves the signal. Still, Freesat or Freeview is much more convenient these days.

If it is Preseli, I suggest marking the pole with a pen to make it easier to point a UHF aerial in the right direction.

The UHF yagi that broke off is a cheap lower gain imitation of the real thing.

The brand name aerials like Antiference, Triax, Blake, etc are made of alloy like the pole and won't rust or bend in the wind. Their gain will be much higher. That yagi was mounted wrongly anyway, the pole was in the way of the dipole and would have reduced the gain hugely, perhaps to the point where it would have been as effective as a rear mounted 10 element flat director quality brand name aerial.

The grid aerials are lower gain than a 10 element flat director quality brand name aerial so it is hard to say why it is there. From the picture it is salvageable, perfectly useable once cleaned up. But even a cheap brand name rear mounted yagi would be better in almost all circumstances, and a rear mounted short x director yagi could be used for more gain. If you use the grid again it should be easy to either put self amalgamating tape all round the side of the box on the dipole or wrap it shut with PVC tape as some can be a bit prone to flapping off in the wind.

If you have to use a Band III VHF aerial for tv bear in mind that it must be mounted with the dipole in front of the mounting pole or it will lower the gain and introduce more noise and interference in an amp. Horizontally polarized it could be mounted half way between the dipole and the reflector. Vertically it could be mounted at the same point with the dipole element as far from the pole as possible or the pole will act like a parasitic element. Ideally, it should be mounted on a short pole at right angles to the main mast, though very few people bother. It may be possible to mount it to the left on its own pole using a galvanized stand off mount and a short pole. That would mean less wind loading on the main pole. Or just mount it at the bottom of the main pole.

Until you find out where your local transmitter is, it is hard to say what can be done. I guess that a large u mount x yagi from a decent brand on top of the pole for Presili and a rear mounted yagi about half way down for the local transmitter may give the best combination of good gain and acceptable wind loading.