Barrie Posted June 26, 2020 Share Posted June 26, 2020 (edited) Dear All, Hoping this isn't a silly question ? I want to use the Clansman mount, (Photo's A & B) with a 2 metre amateur radio set in my LR wolf. In the top part of the mount (Photo C & E) there is a transformer / balun. If I by pass the transformer / balun (Photo F) and use a quarter or five eighth wave length of Clansman aerial rod. will that suffice or am I missing something ? Thanks, Barrie 2W1GMM Edited June 26, 2020 by Barrie Quote Link to comment Share on other sites More sharing options...
snowdrop358 Posted June 27, 2020 Share Posted June 27, 2020 It's got to worth a try? vswr meter should tell you the success or not AND it's easily reversible. PLEASE post your success (or deferred success)! Quote Link to comment Share on other sites More sharing options...
Barrie Posted June 27, 2020 Author Share Posted June 27, 2020 Thanks for the reply And that was going to be my next route, however my friend has offered to respray the Wolf so everything on hold at the moment until Wolf prepped, sprayed and ancillaries bolted back on. will keep you updated Quote Link to comment Share on other sites More sharing options...
snowdrop358 Posted June 27, 2020 Share Posted June 27, 2020 All received and understood 😁 Quote Link to comment Share on other sites More sharing options...
gordonb Posted June 28, 2020 Share Posted June 28, 2020 It isn't a balun as you are going from unbalanced co-ax to an unbalanced whip. I believe from memory that it is an auto transformer designed so that there is a DC path from the whip to ground/vehicle chassis in case of contacting overhead power lines. It may or may not work effectively on 2m. Being designed for the mil band the ferrite may not be suitable. I think I would remove it and just feed the co-ax straight to your quarter wave whip cut for 2m. Or you could do some tests with and without it to some distant friend and try and see if the received signal strength changes with and without it. Quote Link to comment Share on other sites More sharing options...
Barrie Posted June 28, 2020 Author Share Posted June 28, 2020 Gordonb, Thanks for the info. Unfortunately it will have to wait a while as a friend has just offered to re-spray the Wolf in a couple of weeks time, so I’ll be slowly stripping everything off the vehicle. When It’s all back up and running and radios, antennas etc installed will try an experiment or two and post the results. Won’t be for a while though. Quote Link to comment Share on other sites More sharing options...
andym Posted June 28, 2020 Share Posted June 28, 2020 As said, it isn't a balun. Just remove it from circuit as you've suggested and then use a VSWR meter to cut a whip to a suitable length. I've done this before and it works. Andy (M0IJH) Quote Link to comment Share on other sites More sharing options...
Barrie Posted June 28, 2020 Author Share Posted June 28, 2020 Andy, Thank you very much.. Quote Link to comment Share on other sites More sharing options...
g0ozs Posted August 30, 2020 Share Posted August 30, 2020 Barrie I have also bypassed the transformers (UnUns?) to allow direct feed of a quarterwave whip on 4m and 6m. They do appear to have an impedance matching role because the 1/4 wave looked nothing like it should to an antenna analyser until the transformer whatever it is was bypassed. One slight caution - the pigtail from the antenna clamp to the tag in the matching unit is getting to be a significant part of a 1/4 wave at 2 meters and is somewhat coiled when assembled, so the correct resonant length of rod is a bit less than expected - this is noticeable on 4m and expect will be quite significant on 2m. Iain 73 de G0OZS Quote Link to comment Share on other sites More sharing options...
andym Posted August 30, 2020 Share Posted August 30, 2020 9 minutes ago, g0ozs said: Barrie I have also bypassed the transformers (UnUns?) to allow direct feed of a quarterwave whip on 4m and 6m. They do appear to have an impedance matching role because the 1/4 wave looked nothing like it should to an antenna analyser until the transformer whatever it is was bypassed. One slight caution - the pigtail from the antenna clamp to the tag in the matching unit is getting to be a significant part of a 1/4 wave at 2 meters and is somewhat coiled when assembled, so the correct resonant length of rod is a bit less than expected - this is noticeable on 4m and expect will be quite significant on 2m. Iain 73 de G0OZS Yes, noticeably shorter than you might expect - around eighteen inches from memory. Andy Quote Link to comment Share on other sites More sharing options...
Barrie Posted September 1, 2020 Author Share Posted September 1, 2020 Iain / Andy Thank you for the info. My LR Wolf is currently with 'the man with a spray gun', should be back in the next day or so and then the start of the build up. I would have expected a 2 metre quarter wave rod to have been around 19 (+) inches. However being shorter is going in the right direction, easier to take off metal than to add it ! .... and the next problem relates to a non working RT320, but I'll start a new post on that. Quote Link to comment Share on other sites More sharing options...
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