Setting up of a microwaves link

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Bton-FM
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Setting up of a microwaves link

Post by Bton-FM » Mon Dec 23, 2019 10:12 am

I’ve got a pace satellite receiver, an AGD Gunn, lm317 bias supply (very crude) and a technomate lnb. Does anyone have any pointers because I have everything setup and I tried scanning the frequencies and Nothing happened... Also does anyone know what terminal is for the Gunn diode on this module?
Merry Christmas
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Re: Setting up of a microwaves link

Post by Tec1 87.5fm London » Mon Dec 23, 2019 10:38 am

Back pin 7v + and case -

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Re: Setting up of a microwaves link

Post by Bton-FM » Mon Dec 23, 2019 10:41 am

Tec1 87.5fm London wrote: Mon Dec 23, 2019 10:38 am Back pin 7v + and case -
This pin?:
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Re: Setting up of a microwaves link

Post by Tec1 87.5fm London » Thu Dec 26, 2019 7:32 pm

Yes

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Re: Setting up of a microwaves link

Post by Bton-FM » Thu Dec 26, 2019 7:55 pm

Tec1 87.5fm London wrote: Thu Dec 26, 2019 7:32 pmYes
Tec1 Do you have the AGD horn with the screw head tuning screw or Allen key tuning screw?

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Re: Setting up of a microwaves link

Post by Tec1 87.5fm London » Fri Dec 27, 2019 12:21 pm

I had all of them

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Re: Setting up of a microwaves link

Post by Bton-FM » Fri Dec 27, 2019 12:52 pm

Tec1 87.5fm London wrote: Fri Dec 27, 2019 12:21 pm I had all of them
Are any of them bad for links because there seems to be mixed opinions on them.Also do you know what screw can replace the tuning screw the one on my horn has broken ?I’ve got an Allen key AGD coming in the mail.

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Re: Setting up of a microwaves link

Post by XXL » Fri Jan 10, 2020 3:53 pm

Don’t bother with anything other than the AGD horns.

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Re: Setting up of a microwaves link

Post by Bton-FM » Fri Jan 10, 2020 5:52 pm

I’ve just gotta get the damn traffic sensor open!

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Re: Setting up of a microwaves link

Post by Bton-FM » Fri Jan 10, 2020 6:20 pm

Just opened it! I think this is the one you lot rave about...AGD220?Shall I leave the iris plates in?BTW, anyone who needs to open an AGD sensor the T20 size star screwdriver bit is what you need.
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Re: Setting up of a microwaves link

Post by Bton-FM » Mon Mar 16, 2020 8:40 pm

Hi everyone
I’ve built a modulator that’s I’ve checked outputs voltage and I’ve got a satcan wired up ,there is a multiturn pot on tuning pin.I have wound the pot up and down several times and I can’t hear anything through the audio output.I am using the agd horn with the Allen key tuning screw.Maybe I need to turn the pot slower ??? I don’t know I have never tuned up a micro link.Any help would be much appreciated.

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Re: Setting up of a microwaves link

Post by Albert H » Tue Mar 17, 2020 12:21 am

You can't use the Pace receiver unmodified. It's looking for a video carrier (and sync pulses) and an offset audio sub-carrier. Have you been inside the Pace receiver? What type is the tunerhead?
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Re: Setting up of a microwaves link

Post by Bton-FM » Tue Mar 17, 2020 6:50 am

I’m not using the pace receiver im using a hitachi tuner

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Re: Setting up of a microwaves link

Post by Bton-FM » Thu Mar 19, 2020 5:40 pm

Has anyone else got any advice on setting this up?

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Re: Setting up of a microwaves link

Post by Bton-FM » Thu Mar 19, 2020 8:40 pm

Im not using the same modulator as the one at the top of the thread btw.

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Re: Setting up of a microwaves link

Post by Albert H » Fri Mar 20, 2020 2:26 am

Bton-FM wrote: Thu Mar 19, 2020 5:40 pm Has anyone else got any advice on setting this up?
Yes. I get a microwave absorption wavemeter and a microwave frequency counter. I then tune the Gunn diode to the frequency I want at its optimum supply voltage (obtainable from the data sheet for the diode). I then tune the cavity for maximum output on the wavemeter....

I then get the LNB connected to the tunerhead, check for the correct voltages for the LNB and the tuner, then vary the tuning voltage on the tuner until I get a fully noise-quietening signal - I usually point both the Gunn head and the LNB at a wall across the workshop - you're less likely to tune to a sprog that way!

Once I have a solid signal, I engage the AFC circuit (it tracks the drifting Gunn diode and also compensates for heating and cooling of the LNB in daylight and at night). I them mark the Gunn waveguide on the transmitter with its parameters, so that the settings are reproducible, and label the tunerhead and the LNB with their settings, too.

I generally find that each particular waveguide type has a preferred frequency of operation. They're all slightly different - maker to maker - but it is perfectly possible to get good quality audio down a link from ANY of the commonly available waveguides. Don't believe the rubbish that some "engineers" have put on this site about "sounds tinny" or "can't get it to sound right". They just didn't bother to read (or couldn't understand) the specifications of the parts they were using.
"Why is my rig humming?"
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Re: Setting up of a microwaves link

Post by Bton-FM » Sat Mar 21, 2020 1:27 pm

What trimmer value do people normally use on the tuning pin, I've got a 100k one on mine?

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Re: Setting up of a microwaves link

Post by Bton-FM » Sun Mar 22, 2020 1:07 pm

Is it necessary to connect the AGC (automatic gain control) pin?

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Re: Setting up of a microwaves link

Post by Albert H » Mon Mar 23, 2020 1:21 am

I did connect it up to drive a signal strength meter on some receivers I did. I got some very cheap "edgewise" little VU meters (for cassette recorders) and relabelled them "Signal Strength". They made the final physical alignment of the receiver really easy because you could just point for maximum signal!
"Why is my rig humming?"
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Re: Setting up of a microwaves link

Post by Bton-FM » Wed Mar 25, 2020 11:44 pm

What happens if you connect the afc first?

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