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Re: What is the best QMX Linear Amp
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I did a nice editing job on the MTL below? but? the rubbish GroupsIO software appeared to lose it.??
Go by stream of consciousness? I ma NOT going to waste more time on it - the original amp was rubbish and should never have gone to market.? Pmax out is about? 20 W and that can't be achieved at 13.8 V without over driving. THe amplifier was realeased with ?a massive SWR problem which was then corrected in firmware.
So says the Deutscher in the attached video.
Wunderbar that they fixed if after selling may be 500 units, ?but what about the poor Smucks who ?bought the early version- any return to base at mafr's cost
to do the upgrade ? NOt bloody likely. This thing is capable of maybe 20 W linear out but NOT with a 13.6 V supply. ?For that it is Much lower
Stay way from these CHino tin shed outfits... crap dumped on market. no recalls if the item is defective.?
The only way to go with this amp is to get one of the firmware upgrade jobs (but how to know)? THat means the second hand price of these is basically negative as the buyer does not know what he his getting.
The OCS ?50 W PA is even worse.
https://www.youtube.com/watch?v=4N2AiXKudpM
one of hte comments -translated.
One of the sections of the video is ?called "Sudden death"
@Funkwelle
8 months ago (edited) SWR problem ================== The SWR problem shown here has now been resolved with a firmware update. In a separate video I show where you get the firmware from, what you need for an update and how to do it: https://www.youtube.com/watch?v=wTAmhfDWz6I SSB distortion ================== OM Heiko, DL1BZ, reports in his blog about another problem: the distortion of the SSB signal, caused by too low a BIAS voltage on the two amplifier Mosfets. In his blog he describes the problem in detail and explains how you can set the BIAS voltage correctly if you also experience the problem: https://bit.ly/3sXycDV |
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FLDigi and QCX mini
Looked for a while and can't seem to find an answer, so here goes:
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Is it possible send CW directly "live" on the QCX-mini with FLDigi and CAT? I suppose putting the macro string into QCX memory is pretty easy as well, but then I have to deal with the knob push
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Brent DeWitt, AB1LF Milford, MA |
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Re: #QMX Glitchy encoders? Not any more ?
#qmx
Hi, Ronan Thank you for sharing this, I remembered that QCX has 10k pull-up resistors and capacitors to ground like on image attached. It is quite interesting solution for QMX. May be chip has resistors internally but maybe some experience add more details. On the other side, contact bouncing can be solved in software part, but adding capacitor and resistors definitely add more accuracy at least for VFO encoder. |
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Re: What is the best QMX Linear Amp
On Sat, Aug 3, 2024 at 12:05 AM, Timothy Fidler wrote:
The MicroPa50 Plus is a completely crap amp .? It has had very bad reviews many have blow up under very little stress .? the Old versions has Zero low pass filters in them so you? ?will l get? please explains from the FCC if you use one of those. THat all explains why Kaching? - cheep .? That might be before? the Plus. version it comes from a bad pedigree . Timothy, I think you may be confusing microPA50 with an earlier kit called miniPA... that one indeed did not come with any LPF (an exercise left for the builder). The microPA50 and microPA50+ both have switchable LPFs for 80-10m... but I'm sure the LPFs could be better. I haven't measured every band on my microPA50+ (just doing CW key-down into a dummy load, sampler tap into a tinySA) but 30m was closest to being outside of FCC regulations at -43dB on the third harmonic, the rest I checked were better than that.
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That said, there's definitely better amps on the market with "real" RF transistors and better LPFs, and you certainly pay for what you get.
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73 Andrew KI7FXL |
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I had the exact thing happen yesterday on 40m. I was able to shut it down with the left decoder switch.
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va3rr .> It was stuck transmitting and wouldn't respond to the paddle or the power button. It did respond to me turning off the power supply, and then |
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I activated a park (US-5000) with v.023 today. Out in the middle of a large state forest there seemed to be no EM noise: 40m was blissfully quiet except for the signals responding to my CQ. I don't know if it was my location or the firmware update, but the QMX really sounded marvelous and was a pleasure to use. Well, it's pretty much always a pleasure to use.
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Great work, Hans!
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On the last update (v.021?) my messages had seemed a little off. So this time I went ahead and did a factory reset and manually re-created my desired settings and re-entered my messages. This might have yielded better (now default) settings for the AGC rather than the experimental ones I'd entered from the forum when it was new.
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At one point the QMX did freeze as I hit the da paddle to return to someone's call. It was stuck transmitting and wouldn't respond to the paddle or the power button. It did respond to me turning off the power supply, and then booted right back into action. The freeze did not recur. I have no idea what random circumstance might have brought it about. |
¿ªÔÆÌåÓýI misremembered! It's 4 bits -> 8 bits! Sorry for the misinformation! Paul -- AI7JR -- Paul -- AI7JR |
Timothy Fidler
Brent DeWitt
Yury SP2RM
Andrew KI7FXL
va3rr
Todd W2TEF
Paul - AI7JR