[Repeater Troubleshooting]

So I pulled the black cap off of my CX455. Nope the CX455 or any other of the CX series are not tunable. Since mine resonates at exactly 477 MHz, quality control at Sirio must have put a CX470 whip on my CX455 or they put a wrong label on a CX470 as my CX455 needs about an inch longer whip.

[Repeater Troubleshooting]

On 2/16/2024 at 7:57 PM, Radioguy7268 said:

That Sirio CX455 antenna requires tuning. The center section slides in/out to adjust the tuning. What frequency did you tune it for? What did you use to adjust the tuning?

If I am reading your post correctly, you've got the repeater putting out 7 watts, with a measured VSWR of 1.0:1 on 462.725 ?  What's the VSWR on 467.725?

Those RT97 repeaters have a really small internal duplexer with poor isolation specs. If you go above 5 watts, you pretty much guarantee desense. I'd try turning down the power to see if the overall performance & balance of the system improves.

 

How does the center section slide in and out for tuning of the CX455? Mine is resonant at 477 MHz using a Rigexpert 650 Zoom. The whip does not budge at all, and there is no documentation anywhere on the webs describing such a procedure. So my question would be what is the procedure to get the whip to slide in and out?

[High Voltage Transmission Lines]

Thanks. That’s another concern of mine with the HVT line towers being a lightning magnet. Arcing over to my tower

[High Voltage Transmission Lines]

I’m wanting to put up a 35 foot tower with a Comet 712EFC on top of it using 1/2 inch hardline. Before I sink a bunch of money into it, I got High Voltage Transmission Lines on Towers within 150 foot of where I would erect my tower and antenna. Would it be a waste of money and time to even consider it from interference? I have several HT’s of different brands and it doesn’t affect any of them. Not sure though if a base would be a different story being that close to the HVT lines? Thanks for your opinions

[Unable to Test a repeater]

Check your offsets. When you key up your transmit frequency should read 467.6250 your receive would be 462.6250

Everything should work if your in range of the repeater and your transmit tone is correct.

[DC Ground Type Antennas]

DC ground type antennas show continuity between center pin and shield as a J-Pole does. My question is what type of polyphaser is used on DC ground type antennas? DC Pass or DC Block? Also what type is a Comet CA-712EFC collinear? Are collinear antennas DC ground type? Confused on DC pass Vs DC block polyphasers. Forgive my ignorance, and thanks for your help