Qintar QAB-II F-type Switch - UK Vintage Radio Repair and Restoration Discussion Forum

Julesomega · 13th Dec 2023, 6:32 pm

These screened 2-way aerial switches are becoming a bit thin on the ground, which is a pity as they are just what you need for switching Band III beams for your DAB radios. One small Yagi is all I need, but I want to switch between two DAB tuners for comparison purposes, and eBay came up with this clunky switch which was sold as "fully operational and functions as intended" but turned out to be only 1-way, so there was nothing else but to crunch open the glued PVC case and see if a repair was possible.

The mechanism is in a casting-alloy housing, the lid bears down on a rotating screen over the contacts. The contacts work neatly to terminate the unused port. The weakness with working versions of these is poor electrical contacts due to imperfect gold plating. Little shreds of what looks like high copper content gold litter the works on mine, and the spring arm which was soldered to the F socket had dropped off leaving only its gold plating still soldered. It now makes intermittent contact so I have to wiggle the lever until it makes contact.

G6Tanuki · 13th Dec 2023, 6:44 pm

Nice work! That looks like a decent quality coaxial switch for HF/VHF/low-UHF applications.

Julesomega · 14th Dec 2023, 12:33 am

Yes, just don't forget the Servisol next time

13th Dec 2023, 6:32 pm	#1
Julesomega Nonode Join Date: Dec 2012 Location: Stockport, Greater Manchester, UK. Posts: 2,311	Qintar QAB-II F-type Switch These screened 2-way aerial switches are becoming a bit thin on the ground, which is a pity as they are just what you need for switching Band III beams for your DAB radios. One small Yagi is all I need, but I want to switch between two DAB tuners for comparison purposes, and eBay came up with this clunky switch which was sold as "fully operational and functions as intended" but turned out to be only 1-way, so there was nothing else but to crunch open the glued PVC case and see if a repair was possible. The mechanism is in a casting-alloy housing, the lid bears down on a rotating screen over the contacts. The contacts work neatly to terminate the unused port. The weakness with working versions of these is poor electrical contacts due to imperfect gold plating. Little shreds of what looks like high copper content gold litter the works on mine, and the spring arm which was soldered to the F socket had dropped off leaving only its gold plating still soldered. It now makes intermittent contact so I have to wiggle the lever until it makes contact. Attached Thumbnails __________________ - Julian It's good here

13th Dec 2023, 6:44 pm	#2
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,410	Re: Qintar QAB-II F-type Switch Nice work! That looks like a decent quality coaxial switch for HF/VHF/low-UHF applications. __________________ A proper amplifier dims the lights when you switch it on.

14th Dec 2023, 12:33 am	#3
Julesomega Nonode Join Date: Dec 2012 Location: Stockport, Greater Manchester, UK. Posts: 2,311	Re: Qintar QAB-II F-type Switch Yes, just don't forget the Servisol next time __________________ - Julian It's good here