Portsdown 4

Locked
Wurlytech+
Posts: 14
Joined: Mon Jun 22, 2020 7:48 pm

Portsdown 4

Post by Wurlytech+ » Wed Jul 07, 2021 4:44 pm

Thanks to Noel - G8GTZ - my earlier request for a 4 way RF switch no longer applies.

However, having completed the Portsdown 4 and built a PA system - initially for 2m and 70cms - (using Mitsubishi 'blocks'), I need to make lp filters for both bands.
I'd be grateful if anyone could point me in the right direction - either ready built units, or circuit details so I can build them myself.

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

Re: Portsdown 4

Post by radiogareth » Thu Jul 08, 2021 6:26 am


g0mjw
Posts: 2329
Joined: Sat Sep 20, 2014 9:15 am

Re: Portsdown 4

Post by g0mjw » Thu Jul 08, 2021 7:56 am

Also worth checking the Dutch RF shop https://dutchrfshop.nl/en/ for example https://dutchrfshop.nl/en/239-2-meter-band

...and AliExpress / Ebay if you only need a low power filter e.g. https://www.ebay.co.uk/itm/193779518114 ... SwJF1fyfrM

The cheap filters will not handle high power but you can only get 5W or so out of a 30W Mitsubishi block before the shoulders become unacceptable.

Searching for RF low pass filter tends to produce useful results.

Mike

Locked

Return to “Wanted Ads Archive”