Advice Required on Precision Antennas Mason Road Stratford Upon Avon

[Spiff]

Good evening : )

We were looking at some radio items at the local boot sale when I got talking to a fellow buyer.

He said he had a commercial 1.3m prime focus dish I could have, a couple of days later I visited his home, the stand and mount were also there in his garden where they had lain for 15 years.

He found the arms and the feed horn in his garage.

The unit originated from a communication site some years ago, today I cleaned up the dish and mount.

The bearings of the mount are fitted with grease nipples, it is still all in great condition despite being out in the weather for so long.

The aluminium dish could do with a coat of paint, but the galvanising on the mount is fine.

It is heavily engineered really nice, made by Precision Antennas Mason Road Straford Upon Avon.

All that is required as far as I can tell is the correct LNB plus a jack to drive it.

It incorporates a skew control.

Some advice please : )

Does the feed horn look like a C band unit ?

What kind of LNB for KU or C band is required ?

Kind Regards Allen

 

[archive10]

Top notch equpiment. Captain Jack has another recent thread on here that extolls the virtues of the mount running a CM180....
Yes the feed horn looks C-band'ish - but that should not deter you.
Nice piece of equipment, with plenty of room for expansion later...

 

[archive10]

If you want to try Ku on this dish-and-mount configuration, a good start could be (Golden Interstar) GI-209P LNB, which is a Ku-band LNB for P/F dishes.
It is a 40-mmm LNB, so not straight-forward to fit your current feed-mount, but Ḯ am sure you can adapt something without much of a fuss....

 

[John]

.... A very nice gift, you have done well.
That dish is a first rate bit of kit, as well as the mount, even though it has a couple of small dents. I have one myself and wouldn't think of parting with it as they are so good. The feed is a Ku Precision Antennas feed and has a magnetic polariser attached to it that was popular in it's day for changing polarity. It's meant to be used on a C120 flange type lnb which is readily available today.
They once was the dish of choice for betting office shops before Channel Master dishes took over.
You can ditch (but keep) the magnetic polariser as they are lossy and use a modern C120 lnbf that will give you both H & V signals.
Also Allen, there is also some very nice looking vintage bits and bobs in the pictures as well .
Keep it and use it ..... it's is superior to most stuff available today.

 

[battenfan]

What is the f/d ratio? It looks kind of shallow, maybe a normal lnb would do fine.

 

[Spiff]

What is the f/d ratio? It looks kind of shallow, maybe a normal lnb would do fine.

Does FD mean face depth as Alanna just suggested : )

I have had a rotatable set up running a couple of years, but I am still not familiar with a lot of the terminology : )
Kind Regards Allen

 

[John]

What is the f/d ratio? It looks kind of shallow, maybe a normal lnb would do fine.

The Precision feed is not designed to be able to fit a modern 40mm feed. The Precision feed as shown in Allens pic has been designed specifically for that dish for a C120 lnb.
Iv'e modified a modern 40mm Octagon pll lnbf to C120 flange to fit my Precision and it works pretty good, but of course, you can buy a C120 lnb off the shelf. I wouldn't mess with the actual Precision feed .... there too well respected to be altered

 

[Spiff]

.... A very nice gift, you have done well.
That dish is a first rate bit of kit, as well as the mount, even though it has a couple of small dents. I have one myself and wouldn't think of parting with it as they are so good. The feed is a Ku Precision Antennas feed and has a magnetic polariser attached to it that was popular in it's day for changing polarity. It's meant to be used on a C120 flange type lnb which is readily available today.
They once was the dish of choice for betting office shops before Channel Master dishes took over.
You can ditch (but keep) the magnetic polariser as they are lossy and use a modern C120 lnbf that will give you both H & V signals.
Also Allen, there is also some very nice looking vintage bits and bobs in the pictures as well .
Keep it and use it ..... it's is superior to most stuff available today.

Yes I am very happy with my find, it is so disheartening to watch equipment rust away in no time, this is built to last.

I was so lucky, he must have been smiling down : )

So a new C120 type should bolt directly onto the part I have that has the support arms, but less the polarity unit, the difference in length does not matter is that correct ?

Could I use a dual C band / KU band C120. ?

I have never tried C band reception so it would be interesting : )

I have read that a dual unit is a compromise and also that a 1.3 is on the small side for C band, though I have also read that some reception is possible on C band with a 1.2 dish.

Kind Regards Allen

 

[moonbase]

Spiff,

An Invacom C120 LNB or an Inverto C120 LNB will be OK for the dish. I have used both types of LNB with Precision dishes and they work fine.

As other replies have indicated, it is very high quality kit and well worth keeping if you intend to dabble in satellite.


Rgds

 

[John]

Yes I am very happy with my find, it is so disheartening to watch equipment rust away in no time, this is built to last.

I was so lucky, he must have been smiling down : )

So a new C120 type should bolt directly onto the part I have that has the support arms, but less the polarity unit, the difference in length does not matter is that correct ?

Could I use a dual C band / KU band C120. ?

I have never tried C band reception so it would be interesting : )

I have read that a dual unit is a compromise and also that a 1.3 is on the small side for C band, though I have also read that some reception is possible on C band with a 1.2 dish.

Kind Regards Allen

That particular feed you have is Ku band only. Butchering that sort of quality dish to enable a C band scalar ring with a dual C / Ku lnbf to be used could be done but could damage and mis-shape the feed arm anchor points on the dish and therefore alter the perfect shape of the dish. Not a recommended thing to do in my opinion on such a quality dish. Remember ....these dishes & mounts are like rocking horse muck to find because of their age and high quality. Will be waiting for my mate Chris (scopus) now to come on & remind me he has two in storage lol.

 

[Spiff]

That particular feed you have is Ku band only. Butchering that sort of quality dish to enable a C band scalar ring with a dual C / Ku lnbf to be used could be done but could damage and mis-shape the feed arm anchor points on the dish and therefore alter the perfect shape of the dish. Not a recommended thing to do in my opinion on such a quality dish. Remember ....these dishes & mounts are like rocking horse muck to find because of their age and high quality. Will be waiting for my mate Chris (scopus) now to come on & remind me he has two in storage lol.

Hallo John, I will use it for KU only, it would be a sin to modify it.

Could I just ask you about my other question as below : -

A new C120 type should bolt directly onto the part I have that has the support arms, but less the polarity unit, the difference in length does not matter is that correct ?

Kind Regards Allen

 

[Terryl]

Precision Antennas Ltd made point to point microwave systems and cellular back haul microwave systems,( 7 and 14 GHz) the LNB mount may/could be modified for a kU band LNB, but the dish may be too small for "C" band.

Also the company was acquired by Andrews microwave in 2006.

 

[battenfan]

Iv'e modified a modern 40mm Octagon pll lnbf to C120 flange to fit my Precision and it works pretty good

Oh right, I forgot about the first pages of that thread. Very peculiar scalar rings I must say.

 

[John]

Hallo John, I will use it for KU only, it would be a sin to modify it.

Could I just ask you about my other question as below : -

A new C120 type should bolt directly onto the part I have that has the support arms, but less the polarity unit, the difference in length does not matter is that correct ?

Kind Regards Allen

The new C120 lnb will fit where you have the magnetic polariser shown in the pic Allen. Skew adjustment is obtained by loosening the 3 small screws and washer on the actual feed, adjust 7 then tighten up.
Can you take another pic of an end view of the black waveguide transition tube to show us as some were not circular all the way through to put it in simplistic terms.
Ta.

 

[John]

Oh right, I forgot about the first pages of that thread. Very peculiar scalar rings I must say.

My fault that .... i started off the thread with Precision talk, waffled on to altering an Octagon lnb and then went off at a tangent and started to waffle on about my Ka band 1.2 Gibby installation .... sozz

 

[battenfan]

Does FD mean face depth as Alanna just suggested : )

I have had a rotatable set up running a couple of years, but I am still not familiar with a lot of the terminology : )
Kind Regards Allen

Instead of trying to explain I just give you a link.

http://www.satsig.net/focal-length-parabolic-dish.htm

But you don't need to worry about it if you are keeping the original feedhorn.

(OT: My C120 feedhorn had a slightly larger inner diameter than normal so I took it off. It was probably designed to work in lower frequencies than todays universal lnbs. John reported "virtually identical" on Precision so you're good to go.)

 

[Spiff]

The new C120 lnb will fit where you have the magnetic polariser shown in the pic Allen. Skew adjustment is obtained by loosening the 3 small screws and washer on the actual feed, adjust 7 then tighten up.
Can you take another pic of an end view of the black waveguide transition tube to show us as some were not circular all the way through to put it in simplistic terms.
Ta.

Hallo John,

I have photographed the polarity swich as well as it has a square at one end .

 

[Channel Hopper]

There are a few small 'dings' visible on the reflector that you can remove with a bit of patience. Measure the diameter with a tape measure, from memory Precision made a 1.2 and 1.5m, but there may have been a 'special' for a client with enough money for a run on reflectors of 1.3m. The mount is about the best one can get, it will work on reflectors up to around 2m.

 

[Spiff]

There are a few small 'dings' visible on the reflector that you can remove with a bit of patience. Measure the diameter with a tape measure, from memory Precision made a 1.2 and 1.5m, but there may have been a 'special' for a client with enough money for a run on reflectors of 1.3m. The mount is about the best one can get, it will work on reflectors up to around 2m.

Hallo Channel Hopper,

It is 1.3m to the edge of the rim.

Yes three dings it looks like two one way and one the other, a piece of rounded wood perhaps and some gentle taps : )

It is very good to hear about the quality, so much of the equipment sold to enthusiasts is poorly protected and not well produced.

The paint pealed off in strips on the bracket of my Primsat aluminium, the bracket did not fit the rear of the dish and bolting it up misshaped it.

I was offered some bits of rubber by SSS which has made me very wary of them : )

I was too buy at the time with other things to pursue it or they would not have got away with it.

Regards Allen

 

[John]

Hallo John,

I have photographed the polarity swich as well as it has a square at one end .

From your first initial set of pic's Allen and the fact that finding any Precision feed accessories is difficult, i was dreading that the black waveguide transition was going to be a WR75 type that was used also on those dishes ..... see pic with WR75 lnb + Precision feed accessory. Yours is circular all the way through so a modern Universal Ku lnb will mate ok.
Re: the dish dinks ..... mine has a couple or so as well that were usually done by some little brat throwing small stones at them causing a dink that was probably only deforming the dish surface by 15mm max with the biggest dink depth at the very centre and personally i would not attempt to remove them as you could end up with deforming more than a 15mm dia dink area. Remember that these dishes are spun to a very very high surface accuracy of +/- half a mill or less. Just my opinion of course.