I’ve tuned duplexers including that Wacom you attempted to tune, using a MFJ259, a handy, a dummy load and a homemade RF probe. Was amazed how close you can get, particularly if you know what you are doing. A spectrum analyser helps being precise and setting insertion loss to levels at which the Q remains decent. I love my Rigol DSA815TG.
Could you have depowered the repeater and coupled the feedline to a portable receiver on the input frequency, at the antenna connection to the duplexor, then at the output of the amplifier, then at the receiver input to determine quickly where the signal was lost? That could have eliminated the new antenna install , new feedline, a tower climb, tuning the backup duplexor. Maybe I am missing something. I last tuned a duplexor 20 years ago. A great episode!!! 73 de N8RL
i have ben into radios for 35 years & i have had several pull my hair out events over the years & 90% of the time its something simple..Like a bad jumper..i fought one for a 3-4 weeks just to figure out it was a bad jumper..I then bought all new Teflon pl259's & so239 Connectors & that was that ! But i may have ben running a little Heat to but i will never tell..lol.
The band reject is way more important than the bandpass over which you spent most of your time. That crude method you used may not always work for band reject without causing desense of the RX. particularly when. running an amplifier. If you don’t have a spectrum analyser. a better way to optimise bandreject is to use a Rf probe and a dummy load to tune the reject for minimum voltage across the dummy on the reject frequency. Even a nanovna should give decent results although it lacks the dynamic range.
Doesn't the FCC say use only the amount of power necessary to establish the contact ? If you're not using an amplifier now, and can work the repeater from Fifty miles, why do you need an amplifier ? 🤔.....?
When he said,
" Dummy Load ", which guy was he talking about ?
Seems theres always one, sometimes more !
😂🤣😂
Make sure you are using RG-214, NOT RG-213 in the cabinet. Double shielded cables. Robert KD4YDC
I used to tune duplexes in a similar way until I bought a Rigol DSA815-TG and return loss bridge. Best money I ever spent for repeater maintenance.
First raule of fault finding .............. it's usually always the last thing you check that is the problem 🤣
I’ve tuned duplexers including that Wacom you attempted to tune, using a MFJ259, a handy, a dummy load and a homemade RF probe. Was amazed how close you can get, particularly if you know what you are doing. A spectrum analyser helps being precise and setting insertion loss to levels at which the Q remains decent. I love my Rigol DSA815TG.
Could you have depowered the repeater and coupled the feedline to a portable receiver on the input frequency, at the antenna connection to the duplexor, then at the output of the amplifier, then at the receiver input to determine quickly where the signal was lost? That could have eliminated the new antenna install , new feedline, a tower climb, tuning the backup duplexor. Maybe I am missing something. I last tuned a duplexor 20 years ago. A great episode!!! 73 de N8RL
i have ben into radios for 35 years & i have had several pull my hair out events over the years & 90% of the time its something simple..Like a bad jumper..i fought one for a 3-4 weeks just to figure out it was a bad jumper..I then bought all new Teflon pl259's & so239 Connectors & that was that ! But i may have ben running a little Heat to but i will never tell..lol.
The band reject is way more important than the bandpass over which you spent most of your time. That crude method you used may not always work for band reject without causing desense of the RX. particularly when. running an amplifier.
If you don’t have a spectrum analyser. a better way to optimise bandreject is to use a Rf probe and a dummy load to tune the reject for minimum voltage across the dummy on the reject frequency.
Even a nanovna should give decent results although it lacks the dynamic range.
Nano vna is not going to cut it😂😂😂
Those hand tools, 😢. Get the club a good set of pliers, wrenches and other assorted tools. Nothing like trying to work with crummy tools.
💔
Not tousandth, it micro or millionth of a volt
Doesn't the FCC say use only the amount of power necessary to establish the contact ?
If you're not using an amplifier now, and can work the repeater from Fifty miles, why do you need an amplifier ?
🤔.....?
This is so painful to watch.
Why is that ? I thought it was informative.
Agreed, very painful. The pass could have been easily field adjusted by finding the highest return loss / lowest swr. Poor troubleshooting skills.