Lnb for Winterhill

The place for discussion about the 4-channel WinterHill DATV Receiver
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G0DDX
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Joined: Tue Oct 10, 2017 8:38 am

Lnb for Winterhill

Post by G0DDX » Fri May 21, 2021 8:41 am

I have got my Winterhill built, and can rx the DATV beacon with out any difficulty on my 1.2m offset with a Bullseye lnb. Love how stable the bullseye is on NB.

I have two other dishes, a 60cm sky with sky lnb and a 1.2m prime Focus with a fairly old but good quality lnb and with both dishes aligned on Eshail sat. I can receive NB sigs with no difficulty on all dishes, although they are DRO lnb's and drift like a good'un (to be expected).
My question is should I be able to get wideband DATV on those DRO lnbs, as I just don't get anything from them, despite working well on ordinary Sat TV.
ie the lnb's work, but cant get any DATV to work.

If its the dro lnb's anyone suggest a 4 port txco lnb (even a 2 port one would do) that I can use instead. I'm not too clever at modifying lnbs, as I have wrecked a couple already, so looking at an off the shelf one if such a beast exists!

Overall having a lot of fun, and a lot of frustration! But I have not thrown in the towel just yet.

Thanks in advance

Geoff
G0DDX
De Geoff
G0DDX

g0mjw
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Re: Lnb for Winterhill

Post by g0mjw » Fri May 21, 2021 8:55 am

I don't really understand the question. Winterhill is not intended for wideband - i.e. commercial TV reception.

The widest band DATV transmission on QO100 is the beacon and you way you can receive that. DRO LNBs are not so good for lower rates, that includes the beacon. A 60cm dish is too small but a 1.2m dish should be OK with a modern LNB intended for digital, but not an old one. The newer DRO LNBs might not be better for stability but will be for phase noise. Low phase noise is important for digital reception. However it may not be good enough to work on 1.5Ms DATV.

You won't find a 4 port TCXO LNB but Octagon do a 4 port PLL LNB. That would probably be good for your application. I have one, but it is locked so comparisons are difficult but I would say the locked phase noise is slightly worse so it's not as good on wider signals as it was before it was modified. Locking means it is very stable and accurately on frequency, but the original crystal was cleaner.

Mike

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Re: Lnb for Winterhill

Post by G8GKQ » Fri May 21, 2021 9:04 am

Geoff

If you are trying to receive the wideband DATV on the WinterHill, that is your problem. The WinterHill does not receive anything over about 4MS.

You could try using MiniTioune sofwtare with a MiniTiouner and you should be able to receive the wideband stuff OK.

Dave

G0DDX
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Joined: Tue Oct 10, 2017 8:38 am

Re: Lnb for Winterhill

Post by G0DDX » Fri May 21, 2021 9:48 am

Ah.. OK perhaps I've badly worded it. When I say WB, I mean DATV as per Amateurs on Eshail sat.
I mean that NB and WB on Eshail refers to NB for Voice / CW / data, and WB is for DATV.
I am not trying to rx commercial stuff on my Winterhill, just Amateur DATV.

What I am trying to ascertain is should my DRO LNB's work with Eshail DATV? I know they drift like hell, but should they work with Amateur Wideband TV transmissions off Eshail?
I can hear the NB sigs (with drift) so I know they will rx at the lower frequencies off Eshail2. Just cant get even the beacon to work via those DRO lnbs.

Its a case of whether the other lnb's I have are suitable. I am beginning to think they are not stable enough (frequency wise) for Eshail Amateur TV reception.

I have these other dishes pointing at Eshail Sat, and was thinking of using them as I have 4 receivers in the Winterhill.

Now't to do with commercial sigs of any kind.

So I suppose the Question should have been does Winterhill need stable lnb frequencies for DATV reception, or will DRO's, or even PLL ones work. The Bullseye TXCO lnb certainly works and works well. I'm just trying to understand the requirements to get something to work.

Also does anyone know of a suitable lnb with a C120 flange as my 1.2m Prime is a C120 flange.

Geoff
G0DDX
De Geoff
G0DDX

m1cdq
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Re: Lnb for Winterhill

Post by m1cdq » Fri May 21, 2021 10:03 am

what you might be finding with the older FRO lnb's is the noise figure is not good enough also the offset. The narrow DATV signals can be difficult to lock on to if the offset is wrong. though the universal offset is 9750. you may need to fine tune your offset up of down abit.
also as you my have noticed when a dro lnb is first powered up its signal wanders a fair bit. power it up and leave it for a good while to settle down( have a cuppa and a read of the BATC mag ) and stabilise. I have used a dro lnb on a 80cms dish and got lock on DATV.
for the wide band DATV ive used and played with serval pll lnb's unmodded and rx the signals.
long term most pll lnb will work unmodded

g0mjw
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Re: Lnb for Winterhill

Post by g0mjw » Fri May 21, 2021 6:14 pm

I made a PLL C120 LNB by taking a C120LNB cutting off the flange and a little of the pipe and an Octagon LNB and cutting off the horn, joining the PLL LNB to the C120 flange using a hose clamp and some thin aluminium sheet.

Mike
Attachments
C120.jpg
C120.jpg (665.52 KiB) Viewed 3544 times

G0DDX
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Re: Lnb for Winterhill

Post by G0DDX » Sat May 22, 2021 2:56 pm

Wow, I am surprised you can get away with something like that at 10Ghz.
I might try that!

Again Thanks

Geoff
G0DDX
De Geoff
G0DDX

g0mjw
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Re: Lnb for Winterhill

Post by g0mjw » Sun May 23, 2021 2:12 am

Don't be surprised, it's only waveguide. The two diameters are the same usually so it is only a matter of getting a good join between them so the RF flies straight past without perturbation. Make sure there is no gap between the tubes and it will be fine. That's exactly how the C120 flange works when fitted to the feed horn. If you don't have a C120 flange you can bore out a bit of aluminium to k=make one and graft it on to your sawn off LNB. It doesn't have to be a good electrical contact, it is merely a way of clamping two bits of tube together accurately.

Mike

G0DDX
Posts: 14
Joined: Tue Oct 10, 2017 8:38 am

Re: Lnb for Winterhill

Post by G0DDX » Sun May 23, 2021 7:36 am

Mike, thanks. Never really played wit waveguide so its a new area for me. I know about it, but no real experience of actually using it. It gives me something to think about. It's a very old dish from the late 80's, (I did a multi TV H-H sat setup in 1989) but its a good one, so loathed to get rid of it, its solid , well built and does not flex.

I'm a little out of my depth here, and just get a little frustrated when I can't get something to work that I know I should be able to do.


Thanks for your time and words.

Regards
Geoff
G0DDX
De Geoff
G0DDX

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