Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- QRPLabs
- Messages
Search
|
Re: QCX 50W Amp attenuator
#20m
#amplifier
#qcx
Tank you very much for all answers, I will do as advised and keep the attenuator, particularly in the light of the fact that it also servers as a matching network, as pointed to by Bojan.
|
|
Hi all. As a CW operator,? the more important parameter is key down to start of audio tone. The start of RF envelope can be delayed significantly from the start of the audio tone (even 13 milliseconds or even more is fine until you start getting into high speed full break-in) without the brain getting confused.? But key down to start of audio tone wants to be pretty quick (I don't know what it should be subjectively but I would estimate less than a millisecond or so.? ARRL's KX3 review only shows time from key to RF envelope.?
Sidetone lag is always something SDR transecivers have to pay attention to, and it's even more difficult to to well when some transceivers are operated remotely.? -Steve K1RF ------ Original Message ------
From "Hans Summers" <hans.summers@...>
Date 9/5/2023 10:02:58 AM
Subject Re: [QRPLabs] QMX sidetone lag?? #qmx #sidetone #cw
|
|
Re: QMX Kit 76444 ordered Aug 14 has the short at Q103 / Q104.
Definitely want to check Q103/Q104. My QMX kit was shipped 8/24, and it had the short. I haven't started building yet, but I did fix the short by using a hot air rework station, and nudging over Q103 (the big one). --n1bs On Tue, Sep 5, 2023 at 12:09?PM James May - VE3ULC via <ve3ulc=protonmail.com@groups.io> wrote: Thank you for your assistance Jim and Jack. |
|
Re: QMX Kit 76444 ordered Aug 14 has the short at Q103 / Q104.
Thank you for your assistance Jim and Jack.
The ham radio community is fantastic. Yes, it can have warts at times, but overall it is great. Jack, I very much appreciate your gracious offer, and I am willing to compensate you for your time and expenses, or at the very least try to do something in kind for you.?I have one kit to repair at the moment, but a good friend of mine, Rick VE3ORY may have a similar problem and I volunteered to work on his as well. Would I be asking too much for two 1N4148s?? I sent you an email from the address on your QRZ page. Again, I very much appreciate the help guys, Jim VE3ULC |
|
QMX blank screen after initial load
New build of QMX.? I think firmware loaded ok for initial load.? Screen lights up but its blank?? Device manager shows com port and audio shows 2 audio devices for QMX.? On and off works but again screen is blank.? Checked and rechecked solder joints, etc.? No smoke and nothing appears to get hot.? Any help, suggestions would be greatly appreciated.? Did search of prior post did not see anything.? Thank you? 73? ?Emory? WM3M
|
|
Hi Hans,
I can't speak for Don of course, but interested in his reply. I can only say I, and a Facebook friend,? have noted a delay between key pressure and sidetone which is causing us to make errors that we wouldn't otherwise make. I cannot comment on any RF delay as I have not attempted to measure it. I also don't know if there is any additional delay with the sidetone irrespective of any RF delay. All I can say is that it is affecting my ability to send at 20wpm in a way that none of my other rigs do, Inc a K2, FTdx10, the Xiegu stable, a couple of TenTecs as well as my QCX and QCX Minis, and the odd homebrew rig. I would personally just be grateful if you could note the issue as yet one more thing to investigate and consider on your long list please! ? Cheers Daimon. G4USI |
|
Hans,
You are correct!! I should have checked my notes on the QCX. Mine ( v1.00f, and v 1.04) both measure 1 millisecond or less on the bench just moments ago. So very sorry. I cannot re-test the QMX but I wrote down my results before it expired so you might wish to test for yourself. I keyed it with a 2N7000 which was driven by a pulse generator. The dual-trace 'scope was triggered by the keying signal across the source and drain of that MOSFET and displayed with the RF sample. Cursors were placed on the end of the negative going key waveform and at the barest suggestion of the start of the RF response. Perhaps the QMX transmission is delayed a bit to accommodate the T/R switching? If so, then the delay might be mitigated by beginning the sidetone immediatly upon keying detection and letting the actual RF proceed normally. The more immediate response would be the feedback needed for the operator and the actual transmission could be a wee bit behind times but would remain its perfect self. I believe that some SDR transceivers do this to avoid the latency. Again, I am SO sorry about the error! I'm gettin' dumber by the day! 73, Don |
|
Re: QDX Rev 2 problem
Alan and the group,
My WSJT-X v 2.5.4 gives my the same options. I changed the input to MONO and no reception. I changed it to RIGHT and instant contact. I took all the input from the group and popped the hood on the QDX. I tweeked the toroid windings and moved things around. Now I get 4.1 watts out on all bands with 9v. I did the firmware reset... So, in the last hour I picked up 4 new grids out in the west, 1 POTA and 6 other stations. Just like old times. I know that's really not how you should trouble shoot but one of your suggestions got things straightened out. Thank you all, I really appreciate the help. 73, Dean N2TNN |
|
Re: Dire need for a part!
Karl, I joined C509 but not seeing messages show up.? Do I need moderator approval? TNX! Bob WA1EDJ On Tue, Sep 5, 2023 at 7:14?AM Karl via <karlshumaker=yahoo.com@groups.io> wrote: I have started a group named "C509" right here on for parts. When my QMX was missing an SMD capacitor C509, Rick, NF6G sent me a few in an envelope. The intent of group C509 is for all of us to list what we have excess and are willing to send. Source should be indicated as well. |
|
Re: QMX Kit 76444 ordered Aug 14 has the short at Q103 / Q104.
Jim, Try looking on the new C509 group.? I think somebody listed some of those on there. 73 Jim N6OTQ On Tue, Sep 5, 2023 at 8:44?AM James May - VE3ULC via <ve3ulc=protonmail.com@groups.io> wrote:
|
|
Re: QDX Rev 2 problem
Adam,
The audio level is set correctly. Transmit shows S???? 3 blinks then pause PSK reporter shows reception reports up to 6000 miles on 3 bands. 80 is closed now. Also, I opened PuTTy and checked all sub-headings. Everything looks good to me with the filters, transmit and audio levels. I did a factory reset while I was there. Dean |
|
Hi Don I keep on hand several ARRL reviews as reference for when I am trying to compare QRP Labs rig performance with others. In particular I have the ARRL reviews of the Elecraft KX2 and K3S. These are very well respected radios and of importance because unlike many big-name manufacturers, Elecraft are known to give high priority to good CW operational characteristics.? The following are the ARRL measurements of delay from key-down to start of RF envelope:? QCX-mini 1ms QCX 2ms KX2 13ms K3S 11ms If QMX has 10ms delay isn't it already?beating Elecraft K3S and KX2, or am I misunderstanding something? What are your other rigs that have 1ms delays from key-down to RF starting? Of course I want QMX to be as good as possibly?possible. So I can look to make it faster but I'd like to understand the complaint better first.? 73 Hans G0UPL On Tue, Sep 5, 2023 at 4:32?PM Don, ND6T via <nd6t_6=yahoo.com@groups.io> wrote: I measured about 10 millisecond delay from key to beginning of transmitted element. Quite significant above 20 WPM, nearly impossible at 35. I didn't measure much difference between RF and the sidetone audio. The element has additional delay from the start of the transmission until it reaches maximum amplitude (for narrow bandwidth) so that delay is even more. I've noticed that on the early QCX as well and have gone to using an external keyer and using that sidetone instead. Most other rigs that I have have a 1 millisecond delay at most. You can get used to it after a while, re-training you reflexes. A bit like steering a big Caterpillar 966 loader: You need to start a maneuver considerably before you need it. I hear big ships are the same way. |
|
Re: Dire need for a part!
Great idea Karl.? I just joined! Bob WA1EDJ On Tue, Sep 5, 2023 at 7:14?AM Karl via <karlshumaker=yahoo.com@groups.io> wrote: I have started a group named "C509" right here on for parts. When my QMX was missing an SMD capacitor C509, Rick, NF6G sent me a few in an envelope. The intent of group C509 is for all of us to list what we have excess and are willing to send. Source should be indicated as well. |
|
QMX Kit 76444 ordered Aug 14 has the short at Q103 / Q104.
Here is the irony. I knew that this was a problem, and I know I should have checked it first or spent the time setting up my regulated power supply, but in my excitement of finishing the kit, I did not and the smoke came out. I have pre-ordered a replacement power supply board, and now I would like to give a go at hot air reworking, something I have no experience with. In the past I made do with a fine tip iron with lots of paste and wick to get them off. However, I now have a board that I can learn with, so I am shopping for an inexpensive hot air rework station, kapton tape and flux pen on Amazon. I also bought an inexpensive Adonstar AD206 microscope and that is a game changer for my ageing eyes. Very pleased with it, and great for removing slivers from my fingers as well.
?Could some kind soul please provide a link to the suggest replacement part for D101 -?1N4148?on Digikey or Mouser? Thank you, Jim VE3ULC |
|
It lives! Another QMX on the air!
I'm pleased to report after meticulous and painstaking care in following the (detailed and excellent) directions I have completed the construction of my QMX kit.
The troubleshooting steps in the manual were GREATLY appreciated - Having diagrams of where to check for continuity was very helpful, and helped me catch a solder joint with enameled wire that did not quite burn through. I will say I had a somewhat tough time getting the LPF toroids to fit in between the caps and thru-hole inductors, and the controls board needed some finagling to get through the display board, but it did all work out in the end, to my surprise and relief. I have confirmed acceptable power out levels on all bands in CW and it connects to my PC, but I have yet to truly put it through its paces.? I was able to get FT8CN on my android to decode, but there was no power out on TX windows and I was unable to figure out why.? I have yet to sort out how to get it to connect to AndFLMsg as well - If I can get those two to connect I will have a pretty fantastic vest pocket portable station. Good luck to the other builders out there, I hope your luck holds as well as mine! -N1EDC |
Don, ND6T
jjpurdum
to navigate to use esc to dismiss