BATC Forum

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.

Try here https://pa3csg.nl/?page_id=21 and here http://www.dj9kw.de/dj9kw/projekte/afu/ ... owpass.htm
Gareth

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