Filters for 13cms....

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radiogareth
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Joined: Wed Jan 06, 2016 9:46 am

Filters for 13cms....

Post by radiogareth » Sat May 08, 2021 3:17 pm

I'm building up bits of kit for 13cms for 'out and about' and to help my front end escape Wi-Fi, sundry other stuff thats around on 2.4GHz etc I'm experimenting with pipe-cap filters. This article does a great job of explaining and developing one. http://www.w1ghz.org/filter/Pipe-cap_Fi ... isited.pdf
With short probes, I can have a 4MHz BW, by adding probe extensions the bandwidth increases to 60MHz but the slope of the filter isn't as good.
So some sort of compromise is needed.
If I am out /P on 13cms, is there a good SPOT frequency to use?
What is the power limit throughput for a filter like this? I imagine that some very high voltages will quickly arise with increased RF power, so maybe RX only.
SATSAGEN pictures help illustrate.....worth adding that insertion loss seems to be under 1dB....
Thanks
Gareth
13cm_Pipecap_12mm probe.jpg
13cm_Pipecap_12mm probe.jpg (137.94 KiB) Viewed 1596 times
13cm_Pipecap.jpg
13cm_Pipecap.jpg (138.98 KiB) Viewed 1596 times

G8GKQ
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Re: Filters for 13cms....

Post by G8GKQ » Sat May 08, 2021 3:58 pm

Hi Gareth

We recommended 2395 MHz for 13 cms ATV in the last CQ-TV. That's what Noel and I will be on during the contest.

Dave

g8gtz
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Joined: Wed Apr 07, 2010 6:26 pm

Re: Filters for 13cms....

Post by g8gtz » Sat May 08, 2021 4:11 pm

Not wishing to be pedantic but 2395 MHz is only suitable for DATV as the band edge is 2390MHz.

Analogue video should be used in the segment 2322 to 2350MHz.

https://rsgb.services/public/bandplans/24/

Noel

radiogareth
Posts: 1215
Joined: Wed Jan 06, 2016 9:46 am

Re: Filters for 13cms....

Post by radiogareth » Sat May 08, 2021 4:20 pm

Right, I'll tweak it up for DATV on 2395 then :-)
Hope to 'see' you then....
Work still in progress, hoping to shift the IF on my old Drake downconverter as per my ramblings on Thursdays net.
Gareth

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