CW chrip on Hermes board( Cyclone3 fpga)

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ve2xx
Posts: 22
Joined: Tue Apr 11, 2017 1:41 pm

CW chrip on Hermes board( Cyclone3 fpga)

Post by ve2xx »

Has anyone had any issues with the 122.88 mhz osc?? 4 yrs ago i replaced the chirpy osc with this https://www.crystek.com/specification/vcxo/CVHD-950.pdf
and its starting again,

tried all kinds of things . DC measurements , fw, sw , switched to Trimble 10 mnhz external GPSDO, same chirp

tks
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w-u-2-o
Posts: 6090
Joined: Fri Mar 10, 2017 1:47 pm

Re: CW chrip on Hermes board( Cyclone3 fpga)

Post by w-u-2-o »

On receive, or on transmit?
ve2xx
Posts: 22
Joined: Tue Apr 11, 2017 1:41 pm

Re: CW chrip on Hermes board( Cyclone3 fpga)

Post by ve2xx »

on Tx OTA,

did the same tests with Orion 2 board and 100D no chirp on tx'd signal
ve2xx
Posts: 22
Joined: Tue Apr 11, 2017 1:41 pm

Re: CW chrip on Hermes board( Cyclone3 fpga)

Post by ve2xx »

UPDATE

after spending several hours measuring regulators and reading about the specs of vco i have pretty much ruled out any issue with the actual 122.88 osc, looked closer into the 10mhz ref osc and it turns out that even after using an external ref that the same chirpy/watery sounding cw on Tx was still there, so tried playing with FW and Sw versions

I finally decided to go back to where i knew the radio worked just fine with Psdr Mrx back in 2018, i looked back at my saved database files and loaded it and the chirp seemed no longer to be there with or without external 10mhz.

I uninstalled Mrx2018 and installed a 2023 version of Thetis 2 10 2.2 reset db , manually loaded my settings and finally no more chirp or watery sound, i also tried the complete chain , Hermes to transverter to amp and monitored signal over the air at a remote site 10km away,

Thought i share my findings

Stu
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