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.
Portsdown 4
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- Joined: Wed Jan 06, 2016 9:46 am
Re: Portsdown 4
Try here https://pa3csg.nl/?page_id=21 and here http://www.dj9kw.de/dj9kw/projekte/afu/ ... owpass.htm
Gareth
Gareth
Re: Portsdown 4
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
...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