Hi Jan PE0SAT, my emails are not getting through to you so I'll post here,
I have had some success so far,
I've made up two lengths of RG213 with 1/4 wave lengths of 75ohm cable on each end. These are to run from the coax relay to the 145mhz Yagi's as the ARRL drawing suggests. N type connectors are used on each end of these cables.
I've tested this as a phasing harness and achieved around 30dB return loss that's with the 75ohm transformer ends in a T piece and 50ohm loads on the end of each cable.
This was tested on my HP8920 using a 50Mhz to 1000Mhz Narda coupler and am happy with the results, so the phasing harness as it is, is centered on 145mhz with a VSWR of 1.06:1.
Next is the delay line, this has got to be an impedance of between 104 to 110ohms, as the antennas are between 52 to 55ohms now this is going to be hit and miss, as you can't get 105ohm coax. However, you can get 93ohm and what I'm thinking is to remove the center conductor of the coax and replace it with a smaller diameter conductor this should raise the impedance of the coax hopefully to around 105-110 ohms, thus achieving the required impedance of the delay line which is called for in that circuit.
The 93 ohms is just too low and I've found with my testing so far it's better to be on the high side of impedance than the low. The 93 ohms seems to look like near enough to 75ohms and acts like another transformer section.
So I'll continue on and keep you in the loop on success or failure.
Thanks for your mail and Best 73's
Frank VK5KV...
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Frank Woolfe