Aerial Part

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I have lost the signal from the outdoor TV aerial so went up the roof to have a look, removed the plastic cover where the coax joins the aerial and found this half disintegrated printed circuit with F male fitting,
can these be bought separately or is it new aerial time?.
TIA.





 
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It's new aerial time.

Have a think about putting up a Log Periodic aerial.
 
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To answer the original question, spare parts are not available for aerials. However, if you knew the make and model number you could trace it to one or more suppliers and ask them whether they have a damaged-in-transit aerial from which parts could be robbed. You might just strike lucky.

To prevent future corrosion, apply generous amounts of silicone grease.

As regards the V10-36L, I would not recommend this as a "one size fits all" solution. We need to know your postcode in order to recommend an aerial. (A bandpass filter might also be required.) We also need to know how many TV points you want to feed.
 
Sam is correct, the aerial needs to fit the job it is doing, having too much metal hanging off your roof is just asking for further problems. As to repair well I have made from scratch. There is no reason why you should not make your own aerial. Last one I made was using stainless steel pipe and followed the basic G4HFQ's design. However slightly modified and know as a Slim Jim. Most of the aerials were invented by amateur radio people and either their name like Yagi or their call sign like HB9CV are still used to describe them.

The idea is to get as much gain as you need with the aerial, however TV presents more problems as the frequency used is rather well spread. In some areas the band of frequencies is larger or smaller than others, which in turn means the type of aerial changes. narrow band aerials are smaller than wide band so if you can use a narrow band this is the better option. We also have vertical and horizontal polarised there is also circular but as far as I am aware not for TV?

Where I live for TV all I need is a dipole. My transmitter is line of sight at night I can see the aircraft avoidance lights. Years ago I would however select an English transmitter as I can't follow Welsh. So around this area there were many aerials which were set up more to stop reception than to receive it where we wanted Winter Hill instead of Moel-y-parc.

So it is not only reception but also rejection which is important in some areas. I am lucky by putting the aerial low I can use the house to shield me from the English TV. Or fitting aerial other side of the house shield me from Welsh TV. When I had a rotator I could select Central, Northern or Welsh TV.

So yes if you want you can repair the aerial although likely not with original parts. TV used 75Ω systems so you can't use IT stuff which is normally 95Ω or ham stuff which is normally 50Ω however all are usually on sale at ham radio rallies. Although interesting most people would find it a PITA working out how to build an aerial for TV they are so cheap to buy.

Even with ham stuff I tend to buy ready made rather than make it myself. Some VHF aerials have to be seen to believe. I have seen 9 x 16 element yagi beams with motorise direction and azimuth computer controlled to track the moon and even then he could only use Morse code the power and aerial used was not good enough to talk across the pond on the two meter band which is close to VHF broadcast radio. Earth - Moon - Earth is rather specialist he had dispensation to use 1kW normally we are limited to 400W.

Today my ham days are nearly over. I was active with RAYNET but that has also died with the advent of the mobile phone. I never really got into HF until the Morse requirement was dropped I was not licensed for HF I only had a VHF and above licence one of the old GW7 guys. From memory you need 9" for TV. And I would support anyone trying to learn about radio. But in real terms likely buying a new aerial is the easy way forward.
 
Thanks Lucid, I kinda thought that would be the case, is the one in the link of decent quality or are they all much the same?.
Thanks.
http://www.ebay.co.uk/itm/Raptor-4G...UK-/160719534822?_trksid=p2141725.m3641.l6368

It's misdescribed. These is no such thing as a digital aerial. There is no such thing as an HD aerial either.
Below 145.000, with exception of RAYNET what little survives, it is digital, be it Morse, SCTV, or AMTOR, they are digital modes, so an aerial designed for 144 to 145 is in real terms digital, above 145 to 146 it is analogue. Most of the band plan is split into digital and analogue in some way, be it 20 meters or 2 meters does not really matter. Maybe not HD but there is HF. As far as TV goes, digital means wide band, and today there is very few places where a wide band aerial is still required. There is no longer any analogue TV, and the band plan is very much reduced from the old analogue days, so any aerial advertised as digital I would steer clear of, as likely designed for the old band plan, so will have far larger wind resistance and weight to today's aerials. Aerials have colour codes which match the aerial to the area. Buying an aerial local one will expect the correct band, but using distance buying you need to stipulate the band required.
 
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One has to accept manufacturers and suppliers often use incorrect names for the items they sell in an attempt to make it easier for Joe Public and of course sell their merchandise. Be it an electronic transformer which replaces the real transformer, a HF ballast which replaces a real ballast or a digital aerial marked when we were changing over from analogue to digital to they claim to help the public in selecting the correct aerial were to get channel 21 to 68 where the digital channels were slotted in any spaces found so you needed the wide band aerial we have now lost 61 to 68 so any aerial marked up as digital with the black end cap is old stock and should be rejected. Today the wide band aerial has a white end cap classed as group T we so groups A,B, and K are unaffected. But the old group C/D and E with green and brown end caps are also now de-funked, but we still have channels 48 to 60 and there does not seem to be an aerial group covering 53 to 60?

In basic terms with a yagi beam the length of the active element often a loop will give the centre frequency of the band covered. The tighter the elements are together the narrower the band covered and the wider spaced they are the wider the band covered, so as the band width increases so does the size of aerial and so also the weight and wind resistance. In the loft it does not matter but outside keeping weight and wind resistance down is clearly a good thing.

There are some tricks like fitting traps so and aerial can be used on different bands but as far as I am aware this is not done with TV aerials. Also you have vertical, horizontal, clockwise circular and anti clockwise circular the last two and not used with TV but most TV aerials were invented by radio hams so some were designed for modes not used with TV.

So with a caravan aerial one has to try and make one which will work with every type of transmitter however in a house this is often not required. I have not seen TV aerials stacked I will assume the wide band width means it is hard to tune but with hams that is a common practice as we don't really want to talk to satellites and when we do we include azimuth with the rotator so we in general want the aerial to cover as wide as area as we can but not into the ground or sky so stacking works well. With the TV we do not need to turn the aerial in use so we can use a narrower beam. But as the beam gets narrower so the aiming of the beam is more critical to the point where wind vibration can effect the signal.

So the whole thing is a compromise between weight, wind resistance, gain, and band width. The are a few really good aerial fitters so Lucid and Sam I know from past posts are very good, and as far as TV goes better than me. However I only need to walk my local streets to know in my area the aerial fitters must just fit what is handy on their van. As said where I live a simple di-pole is good enough, no reflectors required and no directors required. So should see in the main loads of 6 element yagi beams as don't think any smaller aerials are made. However may be a pre-digital idea of having aerials pointed to Winter Hill instead of Moel-y-parc but I see a whole load of really long aerials pointing is all sorts of directions as direction where I live hardly matters I am sure I could receive Moel-y-parc with a bit of wet string.

In other words location matters. Also some aerials are tuned, the HB9CV is a good example, a really good aerial with two active elements instead of one, really liked by hams as light and handy to work summits on the air. But for TV work the tuning is a pain so not seen any used for TV. This add is typical it gives the weight as 2580 kg hang on that's nearly a ton! It shows a back mount so wind will try to turn it at 16 db gain but nothing to show any other details. This one is centre mounted so less effected by wind, however all it says is 11-14 db and band Ch 21 to 69 so clearly old stock as we no longer have 61 to 69 channels. The more adds I look at the worse is seems to get. At last I got an advert that gave details It gives weight, db gain, beam width, and channels covered at last an add with details. However for me I don't need 16 db gain.

Happy hunting. I would use link given by Lucid if she recommends it that firm will be good.
 
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At last I got an advert that gave details It gives weight, db gain, beam width, and channels covered at last an add with details. However for me I don't need 16 db gain.
It states Forward gain is 11.3 dBd. That's not what I'd call "high gain". In fact it only just exceeds that of a V10-36L and, bearing in mind that 11.3 is the peak gain, its overall gain will actually be lower than that of the V10-36L, whose gain spread is almost linear across the band. Here's a comparison graph with relatively high-gain Yagis at 13.5 dBd and moderately low-gain logPs.

yagi_graph6.gif
 
Sorry I was not saying it was a good aerial just that is actually gave some details.
V10-36L (4G), channels 21 - 60, 10 dBd, 1.28 m long, Needs a signal of at least 28.5 dBuV/m, price £17.99.
No weight given. It says in all the writing it can stand birds I have seen that before with aerial adverts and seen what happened when the Johnny Rook landed on it. And all shooting at the Johnny Rock did with a 12 bore was knock even more elements off the aerial. So even this respected site is very lacking on information. Where I live big problem is the wind, any aerial needs to be mounted at the centre of the wind resistance or likely it will turn the aerial. And pictures show it rear mounted.

To compare aerials you need weight and wind resistance torque as well as db gain. OK local aerial fitter may know if the aerial is likely to be rotated in the wind of that area. But without knowing the area or location you simply can't say a log periodic is better. For my house aimed at Winter Hill which means fitting high up the centre mounted aerial is better. For Moel-y-parc where the aerial can be mounded much lower out of the wind then log periodic would likely be better. However a simple loop aerial would be ample for Moel-y-parc.

It was you who said to start with there is no one aerial fit all. This
product_thumb.php
is the aerial I need with minus DB gain but unless I make my own seems no one sells them for TV use.
 
Sam is correct, the aerial needs to fit the job it is doing, having too much metal hanging off your roof is just asking for further problems.
I've no problem at all with the idea of choosing exactly the right aerial for the job. If all the frequencies to be received are bunched in a tight little knot, and you know for absolutely certain that there no chance of that frequency distribution changing any time in the foreseeable future (let's say 10-15 years) then definitely go for a grouped aerial because it will give more gain and a greater signal to noise ratio. The problem is though that the goal posts keep shifting.

Successive Governments have sold off bits of the TV spectrum for mobile communications, and they continue to see this as a bit of a cash cow so there's every chance that even more bits of the spectrum will be hijacked. The result is that Freeview TV owners have had to retune over and over again because the channel allocations keep shifting. In my own home region (N.W. England) fed from Winter Hill the channel allocation no longer suits grouped aerials at all. Even the so-called "wideband high-gain" aerials struggle. Some services are on c31 and others on c59. Any other single commonly-available aerial other than a Log Periodic is going to struggle to give reasonably-equal reception results over such a wide channel range.

As for limiting the amount of metal in the air, Logs have the smallest profile and lowest wind loading of all the the common or garden variety TV aerials on sale today, so what exactly is your point?

There is no reason why you should not make your own aerial.
If you're a masochist, maybe. The rest of us live in the real world where we just want a good solution with the minimum amount of hassle.



The way I see it is that TV reception is now becoming something of a battle where one is trying to counter the moves of the Government's edicts about how much more of the TV spectrum they plan to sell off. On that basis then luck favours the prepared, and for a good chunk of TV viewers across this country that means having an aerial that is good at picking up the entire spectrum. It doesn't suit everybody of course; that's where local knowledge come in to play. But as far as I am concerned then a Log Periodic is as close as we have right now to a solution that works for many where they can add some in-line filtering if required to fine tune the signal the the TV finally receives.
 
I have to agree with all you have said. The only problem with log periodic is in high wind you want a centre of wind resistance mount so wind will not blow it around. That is still possible with a log periodic but seems rarely done.

Personally I gave up with Freeview and used satellite or internet for all TV. I may stick an very small aerial back up as there are one or two programs one needs to pay for with satellite but are free with Freeview.

I love making aerials, however not tried with frequencies which I can't transmit on. Started on the Falklands with a 8 element yagi made from copper water pipe for the 2 meter band. However always tuned by transmitting and measuring the voltage standing wave ratio (vSWR) which I can't do with TV. In the old days there was nothing on the TV to help tuning, but today we have a good on screen signal meter so in theroy yes we could make our own. However I have a couple of old aerials so easy method is simply cut it short and mount on the back of the satellite dish pole on side of garage.

My TV is not bad a Panasonic it says press select button to retune when it changes. Mothers is a nightmare a LG and have to go all the way through the menu each time there is a change I feel like when channel 5 started which required items to be re-tuned the government should insist every time they swap frequency the people responsible for the change should visit all retired people and retune their set for free. Mother now has no freeview, just a HD satellite box. And no way would I try setting up Freeview for her again. It cost me £25 last time I needed to call some one out to fix it and it lasted 6 weeks and all swapped again.
 

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