Developing the G8ADE sequencer [CQ-TV 125] for Portsdown

Discussion about this major DATV Project. See https://wiki.batc.org.uk/The_Portsdown_Transmitter
M0YDH
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Re: Developing the G8ADE sequencer [CQ-TV 125] for Portsdown

Post by M0YDH » Mon Jan 08, 2018 12:57 pm

Yes please Dave to pictures and a circuit diagram when you're ready. It's a grey area of the Portsdown project. I've been working with the suggestion on the band switching page of the Wiki because I don't know any better!

Regards
David M0YDH

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M5TXJ
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Re: Developing the G8ADE sequencer [CQ-TV 125] for Portsdown

Post by M5TXJ » Mon Jan 08, 2018 1:29 pm

Will do David, it's a little way from finished yet but I've uploaded a short video to Youtube of first test. From left to right the LEDs are;
Blue = power
Green = power to bias tee
Yellow = RX line grounded
Orange = aerial changeover to TX
Red = TX amp enabled.

https://youtu.be/pibFievDoKw

73 Dave
...are you sure I can't use a pair of 813's?... :shock:

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M5TXJ
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Re: Developing the G8ADE sequencer [CQ-TV 125] for Portsdown

Post by M5TXJ » Tue Jan 09, 2018 12:33 pm

Some pictures of my sequencer as promised. I'll draw up the circuit at some point this week.

73 Dave
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...are you sure I can't use a pair of 813's?... :shock:

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M5TXJ
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Re: Developing the G8ADE sequencer [CQ-TV 125] for Portsdown

Post by M5TXJ » Tue Jan 09, 2018 1:17 pm

Now controlled by the Portsdown, I'd better think about a PA next...

https://youtu.be/PGWkAjb03jg
...are you sure I can't use a pair of 813's?... :shock:

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M5TXJ
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Re: Developing the G8ADE sequencer [CQ-TV 125] for Portsdown

Post by M5TXJ » Tue Jan 09, 2018 8:22 pm

OK here's the circuit diagram - not showing the coax relays (don't forget back emf diodes) or the on off switches (power and preamp power). I'm sure you can work the rest out for yourselves. As seen in the photo's I just used veroboard.

73 Dave
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...are you sure I can't use a pair of 813's?... :shock:

M0YDH
Posts: 264
Joined: Sat Dec 31, 2016 5:59 pm

Re: Developing the G8ADE sequencer [CQ-TV 125] for Portsdown

Post by M0YDH » Tue Jan 16, 2018 11:21 pm

Very impressive Dave.
I connected the Portsdown to my relay sequencing circuit and was able to trigger the Mini-kits amplifier. 3 amps drawn. No power output. Next problem 😣

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