I have tuned up several 400 MHz duplexers on 1290 MHz.
No mods, just tuning.
Start my tuning up the duplexer in the 400 MHz band.
Say your output is 1290 MHz? ? Tune up one side of cavities on 430 MHz? ?1/3rd.
Then the same for the other cavities
Now tune them up at the 1290 MHz frequencies.
The 3rd harmonic resonance is not exactly 3X of the fundamental, but it is close.
Tuning at 1290 has the probability of tuning on many of the spur frequencies.
Keep the band active!? ?73 Kent WA5VJB? ?
Chairman? Texas VHF FM Society Technical Committee
On Tuesday, April 9, 2024 at 05:37:49 PM CDT, August Johnson KG7BZ <augjohnson@...> wrote:
Does anyone have a 23cm duplexer available? Or maybe instructions for converting a 70cm?Sinclair Q3220E to 23cm, I have several to use? I have this ICOM ID-PI1200VD sitting here that I'd like to get on the air for a few of us who have ID-1's.
I've seen the info at??I might be able to work along those lines, only for a duplexer, don't need the additional port for the DD radio.
