David try looking at https://www.worldcat.org/title/very-high-frequency-techniques/oclc/1619058 UCL and the British Library have a copy Close but not the one you are looking for, I have the RSGB VHF T

Andy If you don't mind a bit of construction, I have lengths of sage wire that can be cut to length and will make a good cheap low power (maybe 10W) 3dB coupler (sage wire is rather like normal 141 si

Hi Andy, Please confirm method of payment and total cost? Regards Mark GM4ISM

Hi Alan Thanks for the heads up Link fixed (or more accurately the file has been re-uploaded!) Never built one for 9cm.. I’ve used Evanescent filters or surplus Ionica ones HI G4JNT has this article h

Hi All I have done a little maintenance on the 9cm pages of my website http://dc2light.co.uk Broken links fixed and some typos corrected. More data on the Ionica PA pin-out ( added expected current re

Hi Ben That should be safe but in addition to sequencing of the supplies, the protection that shuts down the 10V line should the -ve bias fail is highly recommended. As others have suggested, using th

Neil Not too bad here but understood.. QRT now Lest see what tomorrow brings Mark GM4ISM

Calling on 110 , 135ETN at the moment listening on Zello, ON4KST Mark GM4ISM IO85AR

Anyone on this evening from Northern G? Good possibility of RS Mark GM4ISM IO85AR

All I suspect the IO85BU comes from the fact that there is another beacon there occasionally and it gets spotted! GM6BIG/B Mark GM4ISM

Steve , all Good to see some activity. Did you manage to take a listen in my direction Steve? Neil was getting good AS from me but as normal the path is just too obstructed for troposcatter It doesn't

Hi Steve I may be about up here in GM IO85AR Troposcatter path loss approx 250dB so we may need a little enhancement but worth a go.. You may well hear me 50W tx 35cm dish Mark GM4ISM

Howard, all As Ken has pointed out, the imbalance caused by a difference in power between sources feeding a hybrid combiner is a vector voltage addition His comments prompted me to finish my excel cal

Hi All To be clear A tight layer of PVC tape is still required over the self amalg. Denso cannot really be used to compress the self amalg. That compression is, I believe, an important factor in seali

Indeed Paul, you are right, that is a major function of the PVC I have often also found water under the PVC but that doesn't mean it is unnecessary, it adds a degree of weather proofing but is not wat

Hi Alwyn, all The PVC tape / Denso layer over the butyl rubber self amalg is there because the self amalg is not UV stable. (You do need to use UV stable PVC and of course UV stable cable ties and cle

Thanks Conrad GL: with the EME system I am pleased to hear you are using 7-16 DIN, they are far better than N ..... with one caveat The fine thread on the connector doesn't take kindly to lateral forc

A few more hints The first layer of self amalg is always minimally stretched, the tighter layers above then press down on it and help fill voids (or that's the theory) As has been said, the 1st layer

Hi Nick and Denis / all I am going to put out some CW on bearing of 166 ETN, toward the rain I’m on KST (but meep not working) in theory also on Zello SHF chat but not moderated yet Mark GM4ISM

I would add that you may like to look for GB3CSB on 985 and GM6BIG/B on .500 both fully QRV and better take off than me, (although much lower ERP) On good aircraft or rain scatter I may be louder You