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Hi Group!
I am happy to report on another QCX (#2332) up and running, mine is for the 20 m band and hence didn’t have the chance to test it on the air yet as by the time I arrive home in the evening during weekdays the band is already “closed”. The only exception being the folks in the digi modes around 14.076 MHz, thanks to them I know the receiver is working well :)

I really enjoyed the construction and the smart foolproof alignment procedure. Thanks again Hans!

I measured the output power with my scope and a 50 Ohm load. Using a 13.8 V power supply the output amplitude is 45 Vp-p, so 5 W as per the specs :) I also tested it with a freshly charged lead-acid battery (12.7 V) and at this voltage level power output is 40.6 Vp-p, about 4 W.

I used the 17m capacitor values in the LPF in case I want to try it in the 17m band. With this filter second-harmonic attenuation for 14MHz is 35dB. As max power is 5W (see below) this makes the rig compliant with regulators requirements (30dB attenuation up to 5W output power)

I am attaching some photos, although cosmetic enhancements in the front panel and the GPS connection are still work-in-progress.

Cheers,

Antonio, EA4LE / KC2HAX

Antonio

nice work - thanks for sharing pictures!?

actually you may be getting more output power than most of -- 3 watts tends to be normal (per manual) at 13.8 volts.?

Beware - go it practice mode before attaching GPS !? (it will put rig into transmit - which I did not expect nor prepare for)

I don't know if anyone has checked receiver performance on adjacent bands (image rejection) -- your data would be valuable.?

enjoy operating the QCX.?

Curt

thanks Curt!
> Beware - go it practice mode before attaching GPS !??
OMG... I wasn?t aware of this :(?
I just installed the GPS and calibrated the system and reference oscillator, before reading your warning :(
Hope is still OK,
I compared the QCX output with an FT-817 and at max power output is similar.