Re: NEED TO KNOW STATUS OF QMX HI BANDS SHIPMENT... Order# 81173 - ORDERED IN DEC 2023
Hi Larry,
Please check this site regularly to estimate when your order will be fulfilled:? You're in #465
73, Wei, AG6AQ
On Thu, Mar 14, 2024 at 12:25?PM Larry, AH6AX < lpwandel@...> wrote: Hans:? I'm unable to get any info from your site re: my Dec 2023 order for HI-Bands QMX (factory built). Order No. 81173. When I go on site and request support, I'm told I need to give my 'ticket #); however, although I submitted a ticket last week, I did not know I was to keep the number.? I then went to site to request status and sent that I did not know number. I've been waiting for an email response with ticket number so I can ask the status of the order that I made in December.... My email is correct but for some reason I can't get the email from QRP Labs... (Yes, I checked spam & junk files...)Please help! Thank you! This forum seems to be the only way I can contact you at the moment!!!
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Re: NEED TO KNOW STATUS OF QMX HI BANDS SHIPMENT... Order# 81173 - ORDERED IN DEC 2023
Hi Larry,
Here is a list of the factory built kits.?
?
You are 463rd in line as of March 14th. I don¡¯t know how many he is making a week right now but 30 a week was the number the last time I followed it.?
--
Colin - K6JTH?
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NEED TO KNOW STATUS OF QMX HI BANDS SHIPMENT... Order# 81173 - ORDERED IN DEC 2023
Hans:? I'm unable to get any info from your site re: my Dec 2023 order for HI-Bands QMX (factory built). Order No. 81173. When I go on site and request support, I'm told I need to give my 'ticket #); however, although I submitted a ticket last week, I did not know I was to keep the number.? I then went to site to request status and sent that I did not know number. I've been waiting for an email response with ticket number so I can ask the status of the order that I made in December.... My email is correct but for some reason I can't get the email from QRP Labs... (Yes, I checked spam & junk files...)Please help! Thank you! This forum seems to be the only way I can contact you at the moment!!!
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what manual.? none was received and i have not been able to find
one online
dave
On 3/14/2024 11:38 AM, geoff M0ORE via
groups.io wrote:
toggle quoted message
Show quoted text
Does the manual not describe what it use is??
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Re: QMX Rev 3 USB connector
I've mentioned this before: before shipping, all boards have their bootloader programmed and verified, and that there are no shorts on the 3.3V rail, and that there is successful USB connectivity. The soldering of the USB connector looks rather bare but there IS a connection. My recommendation to touch up with some extra solder is only to strengthen the connection which looks a bit delicate for my liking.?
73 Hans G0UPL
Yep. Mine looked the same.Took Han's advice and touched them up.
Super pointy iron tip, turned down the heat a bit and easyyyyy on the solder. I have a bit of 0.015 inch solder. Goes fast. I do use a head lamp magnifier, board holder armature and anchor my little fingers somewhere on the edge of the pcb or armature when possible so my iron and solder feed motions are as steady as possible.
Easy to create bridges here ... Yep did that also in two places though they were minor. Just reheating one pad side briefly with a clean tip that has no solder on it caused the bridge to whisk itself back into the heated pad. Whew ...
In hind sight, might just leave them as is and see how it works on startup. Can always go back and touch them up.?
Greg KI4NVX On Thu, Mar 14, 2024 at 10:51 AM, Rich Collins via Almost completed building my low band QMX and the usb connector soldering looks poor. Hans, is this what you have mentioned? Do you advise I touch it up?
Also, I found the BNC connector needs to be fitted? angled slightly forward, so as not to foul the display board.
I'm a cw op, no digi modes.
Richard
G4PCE
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Does the manual not describe what it use is??
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Re: 50W Amp Curious Questions - Why does 40 meter AMP put out so much more gain?
#50w
#output
Thx Adrian, Hans and Allison.
Appreciate the feedback.
Will proceed carefully.
Greg
On Thu, Mar 14, 2024 at 9:49 AM, Adrian YO3GFH via groups.io <p_adr@...> wrote: Hi Greg,
AFAIK, IRF510 was designed to be a power switching device. Many years ago, some kind soul found that it can also be used as a low cost HF power amp, with more than decent results. But, as there's no free lunch in this universe, so is the case with IRF510 - due to it's internal capacities, it works best in the low bands and kinda so-so under 20m.
Incidentally, my first amp that didn't oscillate and actually worked was a IRF510 design for 80 and 40 meter, published by a DL ham. It was 25 years ago, I think I still have it somewhere under the bed :-)?
Using some sort of resistive attenuator is probably a good idea, if you can't power the QMX from something lower than 12V. While tinkering with atten. and bias, it would be nice to have a scope to make sure that you actually output a sine.
Regards,
YO3GFH
op. Adrian
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Re: 50W Amp Curious Questions - Why does 40 meter AMP put out so much more gain?
#50w
#output
15M? results say the amp has issues. Either low bias or LPF filter??
20M 10W for 2 in seems? a bit low as well (I'D expect 13-15W)
At the same time the 40M results suggests maybe other things going on.
For 40M at 3W in I'd expect about 17-25W at 13.8V.? Part of the reason
is there was no intention to get flat gain from the amp.? No surprise with
a class C amp.? Hoeever if the bias is set high you do get more power
and possibly other things like spurs.
The IRF510 is performs poorly at lower voltages that why at 20V it can easily do 50W
but at 13.8 you may get around 20W.
Oddly I have an amp that uses MRF141(dual) and at 28V its easily 330W, but at 13.8V
it barely does 90W for the same drive.? THis is often seen with all Mosfets and Bipolar
devices because whne you lower votlages characteristics change.
--
Allison
------------------
Post online only,?
direct email will go to a bit bucket.
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Re: 50W Amp Curious Questions - Why does 40 meter AMP put out so much more gain?
#50w
#output
Yes, 100% agreed with Allison.?
MOSFETs don't have an intrinsic frequency limit like a bipolar. Which is also why good board layout and attention to parasitics is important because you can easily get VHF oscillations.?
But as Allison said the gate capacitance is the issue. Which in other words means it gets harder and harder to match the ever lower impedance efficiently as you go up in frequency.?
Even though the IRF510 is often accused of only being a car headlamp switching transistor... These capacitance and impedance issues affect even "real" RF MOSFETs as much or almost as much.?
With careful feedback and layout as in the 10W Linear amp kit the gain can be made quite flat across HF 1.8-30MHz to within a dB or two.?
The 50W PA kit was a much more basic design effort originally done for 40m where everything is easiest as Allison mentioned. Reasonable worthwhile performance obtained up to 20m made those acceptable options too. I'm not surprised 15m was even lower down.?
73 Hans G0UPL
On Thu, Mar 14, 2024, 7:30?PM ajparent1/kb1gmx < kb1gmx@...> wrote: I have a linear amp that gets over 40W at 6M using IRF510s.
Wasn't hard to do that.
The characteristics are not great but its not about capacitance as
a sole factor.? Then again input Z is a factor even MRF and BLF series
MOSFETs.
The problem of wideband amps with MOSFETs is input and output matching.
The gate is a capacitor and that makes input matching difficult.? Most designs
using IRF510 or IRF530 40M is a sweet spot.? The problem being input
impedance goes down with increasing frequency.
Develop voltage at the gate effectively you get power out.
--
Allison
------------------
Post online only,?
direct email will go to a bit bucket.
|
Re: 50W Amp Curious Questions - Why does 40 meter AMP put out so much more gain?
#50w
#output
I have a linear amp that gets over 40W at 6M using IRF510s.
Wasn't hard to do that.
The characteristics are not great but its not about capacitance as
a sole factor.? Then again input Z is a factor even MRF and BLF series
MOSFETs.
The problem of wideband amps with MOSFETs is input and output matching.
The gate is a capacitor and that makes input matching difficult.? Most designs
using IRF510 or IRF530 40M is a sweet spot.? The problem being input
impedance goes down with increasing frequency.
Develop voltage at the gate effectively you get power out.
--
Allison
------------------
Post online only,?
direct email will go to a bit bucket.
|
Re: QMX Rev 3 USB connector
Yep. Mine looked the same. Took Han's advice and touched them up.
Super pointy iron tip, turned down the heat a bit and easyyyyy on the solder. I have a bit of 0.015 inch solder. Goes fast. I do use a head lamp magnifier, board holder armature and anchor my little fingers somewhere on the edge of the pcb or armature when possible so my iron and solder feed motions are as steady as possible.
Easy to create bridges here ... Yep did that also in two places though they were minor. Just reheating one pad side briefly with a clean tip that has no solder on it caused the bridge to whisk itself back into the heated pad. Whew ...
In hind sight, might just leave them as is and see how it works on startup. Can always go back and touch them up.?
On Thu, Mar 14, 2024 at 10:51 AM, Rich Collins via groups.io <richanny@...> wrote: Almost completed building my low band QMX and the usb connector soldering looks poor. Hans, is this what you have mentioned? Do you advise I touch it up?
Also, I found the BNC connector needs to be fitted? angled slightly forward, so as not to foul the display board.
I'm a cw op, no digi modes.
Richard
G4PCE
|
Almost completed building my low band QMX and the usb connector soldering looks poor. Hans, is this what you have mentioned? Do you advise I touch it up?
Also, I found the BNC connector needs to be fitted? angled slightly forward, so as not to foul the display board.
I'm a cw op, no digi modes.
Richard
G4PCE
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Re: QMX - Any progress on key clicks please?
Mine clicks as well. I turn the volume down when sending and the clicks disappear and then turn it back up as soon as I¡¯m done sending to avoid hearing them.
73, Matt AE?XR
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Re: 50W Amp Curious Questions - Why does 40 meter AMP put out so much more gain?
#50w
#output
Hi Greg,
AFAIK, IRF510 was designed to be a power switching device. Many years ago, some kind soul found that it can also be used as a low cost HF power amp, with more than decent results. But, as there's no free lunch in this universe, so is the case with IRF510 - due to it's internal capacities, it works best in the low bands and kinda so-so under 20m.
Incidentally, my first amp that didn't oscillate and actually worked was a IRF510 design for 80 and 40 meter, published by a DL ham. It was 25 years ago, I think I still have it somewhere under the bed :-)?
Using some sort of resistive attenuator is probably a good idea, if you can't power the QMX from something lower than 12V. While tinkering with atten. and bias, it would be nice to have a scope to make sure that you actually output a sine.
Regards,
YO3GFH
op. Adrian
|
Re: QMX - Any progress on key clicks please?
I tried factory reset and f/w017 reload with no change in clicks ?- ?still there. Power cycle or no, any and all changes in settings and it's still the same.?
?
If I turn the volume down to zero or just above, I get no clicks and as I turn up the volume, the clicks just get louder and louder.?
?
*** I think the following is why there is such disparity between different observers: ?If the Side Tone is set To Relative instead of Absolute, then the clicks are much, much less and only become objectionable when the volume is turned up to distorting levels.***
?
I believe it has to do with the tx>rx change over. However, that doesn't quite explain why it is so much worse with Absolute rather than Relative ST volume.
I believe the f/w needs to do what was done in h/w on the QCX. Of course, I am no programmer and I haven't a clue HOW that can be done, but I'm pretty sure it CAN be done. After all, it's been done on many other SDR radios
-- 73, Dan? NM3A There are moments when everything turns out right .... Don't let them alarm you; they pass.?
-Jules Renard
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Re: 50W Amp Curious Questions - Why does 40 meter AMP put out so much more gain?
#50w
#output
It¡¯s possible the 40M amp is oscillating. Also possible that the input Pi attenuaor has an issue.?
I have 2 of those 40M amps and one gets 25W with 4 W in at 13V
2nd gets 50W with 4W in at 22V
Larry KB3CUF?
On Thu, Mar 14, 2024 at 7:13?AM Greg McCain via <gamccain50= [email protected]> wrote: Yes.
K2 - 50W Amp - QrpGuys SWR/Power meter.
Greg On Thu, Mar 14, 2024 at 12:29 AM, Larry Acklin Hi- is this into a watt/swr meter then dummy load?? Antenna connections with SWR issues can fool inexpensive watt meters.?
Larry KB3CUF? On Wed, Mar 13, 2024 at 11:23?PM Greg McCain via <gamccain50= [email protected]> wrote: Hi gang,? Not complaining ...? ?Just curious.
I had recently built 3 of the 50W amps ( 15M, 20M and 40M). Want to use them for a little extra punch (say 10 to no more than 20 watts out) for field semi-portable 'digi' work (FT8, J8Call, WSPR) . . .? well, just because.??I built all three as '12 volt' versions.?
?I set the drive bias exactly as described in the instructions. The builds went well and the amps appear to output as described in the manual(s)./graphs.
I was just wondering why the 40 meter version is 'hotter' than say the 20 meter version which is hotter than the 15 meter version.
I found that I can get 10 Watts OUT with the following Watts IN from my K2.
15M - approx 4.5 Watts IN
20M - approx 2 Watts IN
40M -? LOTS of WATTS OUT (Too Many) with Just 1 Watt in !!
** For the 40M, I found if I backed down the bias, I could get 10 Watts out by setting the K2 for between 0.1 and 0.2 Watts out. Yep 'tenths' of a Watt.?
Is my stumbling on the bias backdown a potential problem point?
Or, perhaps I should make up some PI attenuator circuits to add to the Transmit circuit chains in the AMPs where needed to tone down the 3.6 - 3.9 Watts that my new QMX is producing??
Thanks in advance,?
Greg? KI4NVX
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Re: 50W Amp Curious Questions - Why does 40 meter AMP put out so much more gain?
#50w
#output
When you see an amplifier provide loads of gain in a particular band or frequency it is usually because there is a circuit self resonance, so losses are minimal, or there is some negative feedback that due to phase shifts is becoming less so. ?It is not much fun when the amplifier gain and phase shifts flip into the positive region and oscillation begins.
toggle quoted message
Show quoted text
On Mar 14, 2024, at 07:13, Greg McCain via groups.io <gamccain50@...> wrote:
?Yes.
K2 - 50W Amp - QrpGuys SWR/Power meter.
Greg On Thu, Mar 14, 2024 at 12:29 AM, Larry Acklin <acklin@...> wrote: Hi- is this into a watt/swr meter then dummy load?? Antenna connections with SWR issues can fool inexpensive watt meters.?
Larry KB3CUF? On Wed, Mar 13, 2024 at 11:23?PM Greg McCain via <gamccain50= [email protected]> wrote: Hi gang,? Not complaining ...? ?Just curious.
I had recently built 3 of the 50W amps ( 15M, 20M and 40M). Want to use them for a little extra punch (say 10 to no more than 20 watts out) for field semi-portable 'digi' work (FT8, J8Call, WSPR) . . .? well, just because.??I built all three as '12 volt' versions.?
?I set the drive bias exactly as described in the instructions. The builds went well and the amps appear to output as described in the manual(s)./graphs.
I was just wondering why the 40 meter version is 'hotter' than say the 20 meter version which is hotter than the 15 meter version.
I found that I can get 10 Watts OUT with the following Watts IN from my K2.
15M - approx 4.5 Watts IN
20M - approx 2 Watts IN
40M -? LOTS of WATTS OUT (Too Many) with Just 1 Watt in !!
** For the 40M, I found if I backed down the bias, I could get 10 Watts out by setting the K2 for between 0.1 and 0.2 Watts out. Yep 'tenths' of a Watt.?
Is my stumbling on the bias backdown a potential problem point?
Or, perhaps I should make up some PI attenuator circuits to add to the Transmit circuit chains in the AMPs where needed to tone down the 3.6 - 3.9 Watts that my new QMX is producing??
Thanks in advance,?
Greg? KI4NVX
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Re: For Sale: Two Assembled QDX Rigs - Hi/Lo bands
Items sold - thanks for any inquiries.
--
Jim / K7TXA
Eagle, ID
SKCC 10447T
BUG 301
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I believe that the EXT jack is for tuning control/triggering by (if I recall correctly) Icom transceivers. I think it is a 3.5mm TRS jack.
The USB port on front is used (on my unit) to charge the batteries.
73, Don N2VGU
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Re: 50W Amp Curious Questions - Why does 40 meter AMP put out so much more gain?
#50w
#output
Yes.
K2 - 50W Amp - QrpGuys SWR/Power meter.
On Thu, Mar 14, 2024 at 12:29 AM, Larry Acklin <acklin@...> wrote: Hi- is this into a watt/swr meter then dummy load?? Antenna connections with SWR issues can fool inexpensive watt meters.?
Larry KB3CUF? On Wed, Mar 13, 2024 at 11:23?PM Greg McCain via <gamccain50= [email protected]> wrote: Hi gang,? Not complaining ...? ?Just curious.
I had recently built 3 of the 50W amps ( 15M, 20M and 40M). Want to use them for a little extra punch (say 10 to no more than 20 watts out) for field semi-portable 'digi' work (FT8, J8Call, WSPR) . . .? well, just because.??I built all three as '12 volt' versions.?
?I set the drive bias exactly as described in the instructions. The builds went well and the amps appear to output as described in the manual(s)./graphs.
I was just wondering why the 40 meter version is 'hotter' than say the 20 meter version which is hotter than the 15 meter version.
I found that I can get 10 Watts OUT with the following Watts IN from my K2.
15M - approx 4.5 Watts IN
20M - approx 2 Watts IN
40M -? LOTS of WATTS OUT (Too Many) with Just 1 Watt in !!
** For the 40M, I found if I backed down the bias, I could get 10 Watts out by setting the K2 for between 0.1 and 0.2 Watts out. Yep 'tenths' of a Watt.?
Is my stumbling on the bias backdown a potential problem point?
Or, perhaps I should make up some PI attenuator circuits to add to the Transmit circuit chains in the AMPs where needed to tone down the 3.6 - 3.9 Watts that my new QMX is producing??
Thanks in advance,?
Greg? KI4NVX
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Colin Kaminski
Larry, AH6AX
Rich Collins
Matt AE0XR
Donald S Brant Jr