Search results

I'm a bit of a newbee here and it is great to see the response to this old original thread. I know from research that Marconi has been following these designs for years, thanks for the input Marconi, I appreciate it. To answer your question Road Squawker. I believe proper tuning is what keeps RF...

Marconi, I have been scouring the internet for everything i can find regarding dual polarity quad beams, particularly the Lightning 4+. What is your opinion, are they as efficient as single polarity? Is tuning an issue? What about the discussion that rf is returning on the unselected coax? I...

Does anyone know how to get hold of Makers Mark from Indiana? I would love to know how he setup the vertical stack. Thanks, dennis

Sirio GM height vs gain and TOA The DB, I would be very interested to see the patterns. I am considering putting up a GM at 84' ~2.2 WL with a 3 element horizontal 10, 15, 20, 40 meter beam 8' below it. Is there anyway to know if there would be an interaction with the horizontal beam below...

Shockwave, Thanks for the additional tuning tips. I originally set both beams horizontal on separate masts 9' off ground spaced 27.5' apart in a clear area 40' from anything as Maco suggests. It sounds like the measurements I took there would be more accurate than on the mast 2.5' off...

Using 50 ohm coax between antennas and co-phase harness Shockwave, I thought everyone might appreciate some feedback from this project. I finally completed the harness for 2 Maco 103c vertically stacked 27.5' apart. It seems to me that SW was correct about adding odd but same length 50...

ALC I get it. Ok, I get the idea. Thanks for the reply, love that line from the movie. :)

Hello, The Icom 761 manual says the ALC voltage must be in the range of 0 ~ -3v while the AL-82 manual says output is between 0-20 volt negative. Are they compatible? Thanks, dennis

JAZZSINGER, I've read that the long runs of mismatched coax (75 ohm) have more loss than 50 ohm extensions. Anyone experimented with that? Thanks for the input, Dennis [QUOTE=jazzsinger;423194] for base I'd use either 2 x 3/4 or 5/4 wave runs of rg11 or better, and 1/2 wave multiples of...

Pl259 loss Very helpful information DB, thanks.

Co-Phasing SW, Yes your assumption that I am not using 1/4 WL whips is correct. I am stacking 2 Maco 103c beams. I posted here because of Marconi's post regarding making a CP harness without a T connector. Also his statement "We found that Field Strength was improved noticeable using the...

Tuning CP harness with MFJ 259B Marconi and others, I have read and understand the MFJ 259B manual regarding tuning stubs and transmission lines. I do not understand ho to apply this to tune the CPH using 2 dummy loads. How do I tune each side? Do I have to solder Pl259s on each end then cut...

Thanks for all the input everyone. It sounds like I would have to spend some extra time checking the tune if I want to use other than 1/2 WL of 50 ohm to make up the difference. I have read that there is less loss using 50 ohm to make up the difference rather than using all 75 ohm 3/4WL because...

Marconi, So I would add a tuned 1/2 WL 50 Ohm line between each antenna connector and the CP harness? I would tune each 1/2 WL and the CP harness and then double check everything together? I have not used an analyzer yet but have a friend that is willing to loan one to me for the...

Also, if i used an MFJ or similar analyzer would I be able to tune the harness using 50 Ohm lengths from antennas to 75 Ohm harness or is there just no good way to tune it when setup that way? thanks again, dennis

Thanks for the quick response Doc and Marconi. This is my first co-phase project so I better make sure I understand :-) If I stack 2 antennas and the SO-239s are 32' apart and I am using LMR-240 75 Ohm my harness would have to be: ((492x VF .84/27.205) /2)x3 = 22.787'? 45.57' end to end...

Using 50 ohm coax between antennas and co-phase harness I know this is an old thread but it is the best description of how to build a co-phase harness I have found. My question is can you use equal lengths of 50 ohm from each antenna in an array to the 75 ohm co-phase harness? I have read...