http://qrp-labs.com/qcx.html (http://qrp-labs.com/qcx.html)
Impressive list of features! I have one on order for 80m.
(http://qrp-labs.com/images/qcx/photos/2.jpg)
- Easy to build, single-board design, 10 x 8cm, all controls are board-mounted
- Professional quality double-sided, through-hole plated, silk-screen printed PCB
- Choice of single band, 80, 60, 40, 30, 20 or 17m
- Approximately 3-5W CW output (depending on supply voltage)
- 7-16V recommended supply voltage
- Class E power amplifier, transistors run cool... even with no heatsinks
- 7-element Low Pass Filter ensures regulatory compliance
- CW envelope shaping to remove key clicks
- High performance receiver with at least 50dB of unwanted sideband cancellation
- 200Hz CW filter with no ringing
- Si5351A Synthesized VFO with rotary encoder tuning
- 16 x 2 blue backlight LCD screen
- Iambic keyer or straight key option included in the firmware
- Simple Digital Signal Processing assisted CW decoder, displayed real-time on-screen
- On-screen S-meter
- Full or semi QSK operation using fast solid-state transmit/receive switching
- Frequency presets, VFO A/B Split operation, RIT, configurable CW Offset
- Configurable sidetone frequency and volume
- Connectors: Power, 3.5mm keyer jack, 3.5mm stereo earphone jack, BNC RF output
- Onboard microswitch can be used as a simple straight Morse key
- Built-in test signal generator and alignment tools to complete simple set-up adjustments
- Built-in test equipment: voltmeter, RF power meter, frequency counter, signal generator
- Beacon mode, supporting automatic CW or WSPR operation
- GPS interface for reference frequency calibration and time-keeping (for WSPR beacon)
Better hurry on this one guys, there is a limited number available...
Gil.
NICE! Thanks for posting that. I just ordered one, also in 80M. It was $55.30 shipped. I don't know how they make any money with the prices they charge. Shipping was cheap enough that I assume they are in the U.S., but I can't find where they are located.
This will be a nice fall project. Naturally I'll design a 3-D printed box and make a few available for members here that have been around a while.
Awesome Bob. By the way I have made the Nescaf filter, and the video is set aside for when I won't have anything to post on Youtube. The only issue with this new kit is having to cut a rectangle window in an aluminum case... Oh well... Other than that it's great!
Looks like I have serial #254.
Gil.
Quote from: cockpitbob on August 21, 2017, 09:34:42 AM
... I assume they are in the U.S., but I can't find where they are located.
I also wondered about that. This is what I found out. The owner of QRP Labs is a British ham:
G0UPL Hans Summers. — Email: hans.summers@gmail.comCheck Podcast Episode #125 here:
Quote from: www.qsotoday.com/podcasts/g0upl
As a 2009 QRP ARCI Hall of Fame inductee - Hans Summers, G0UPL, is an electronic experimenter and amateur radio innovator extraordinaire. Hans pays careful attention to compact and minimal parts count to achieve the design goals of his homebrew projects. Hans is the owner of QRP Labs joins Eric, 4Z1UG, in a conversation about QRSS slow data transmissions, high altitude balloon transmitters, and shares his ham radio and electronic builder story.
Websites:
http://www.hanssummers.com/home.html (http://www.hanssummers.com/home.html)
https://www.qrp-labs.com/ (https://www.qrp-labs.com/)
https://shop.qrp-labs.com/ (https://shop.qrp-labs.com/)
https://www.facebook.com/QRPlabs/ (https://www.facebook.com/QRPlabs/)
https://groups.yahoo.com/neo/groups/QRPLabs/info (https://groups.yahoo.com/neo/groups/QRPLabs/info)
Edit: I removed his complete home address, found on QRZ.com. All other information is publicly available.
Gil, I can't wait to hear what you think of the filter. I built my filter and Pico-Keyer and but haven't quite finished the box to put them in, so I haven't tried the filter yet.
Sparks, thanks for the background on qrp-labs.com. I got the sense they were from across the big pond, which makes the low shipping cost impressive.
Same here Bob, no case yet. The filter works fine. It does add a bit of complexity to a rig with the added wires. A better thing to do might be putting it in a box along with the transceiver PCB... Or making a battery/filter/speaker box...
Gil.
I've been looking at this QRP Labs kit all week and finally decided to order a 20 meter version. It looks pretty complex for the price. Now I will have to brush up on my CW skills. I hope somebody makes a after market case for it, I bet they do.
Joel
N6ALT
Thanks Gil! So great and useful to be on RadioPreppers.com! I bit the bullet immediately, as need at least ONE QRP rig sooner than later, while I dilly and dally and save up for e.g. PFR-3b. I ordered one for 30m. Impressive that it has a CW decoder built in, not much use if you cannot send CW, but useful perhaps for when you are sleeping and someone else is keeping watch on frequency. Nice that it has, presumably also beacon mode, for auto CQ. I chose 30m due to all-round propagation: possible for DX every day (or night) but also good regional coverage. In higher latitudes not as useful as 40m, and not nearly as many stations available as on 40m, but, I like the DX. Noise levels there during TWAWKI are also much lower. But for portable use and TEOTWAWKI probably 40m would have been much more useful. One can always order another one hopefully, later, always good to have 2 different rigs in case one breaks.
Caulktel I hope there is a case too. Still, it'll work without one, we hope :-)
Shipping is from China. If they smuggle them across to Laos it'd be even cheaper!
I'll report my number when known so we can see how fast they are going, I bet fast.
Good voltage range 8-14V wonder if 8V really produces 3W and how much 12V produces.
200Hz CW filter with no ringing sounds good, though hopefully it also allows filter to be off/wide?
Got my serial number, it is over 600! "your order is a PRE-order for a kit from the second batch of 500, which is expected mid-September." Unsurprisingly this is popular. Unsurprisingly many found out about it before we did, but I'd not have known if not for RadioPreppers.com!
I ordered mine a few days ago and it's serial number 301. I just checked their website and to they just shipped #175. Looks like I got in just before a big run on them.
You should have told me I'd have ordered mine a few days ago ;D
SWXX,
Mine is number 628. Also, I believe Hans ships from Japan.
Joel
N6ALT
Gil,
According to the instructions you are going to have to wind your toroid messy because it's for 80 meters, sorry:-(
Joel
N6ALT
Darn, oh well... I wish I could also get one for 30m too. I was just thinking that if I bought a 2-band K1 I would choose 30 and 80m... If I could have only one single band radio I would get a 40m rig, but I already have a bunch of those...
Gil
Sent from my SM-G928F using Tapatalk
Meh, the 5 toroids to wind doesn't look too daunting.
I just downloaded the assembly/user's manual. 137 pages!!! It's very nicely done! This is clearly a labor of love.
It has power consumption curves for Rx and Tx for the various bands. Rx is a little high at 130mA. The backlight current is 15mA, so running that through a switch could save a little. But then, with a battery pack of three 3,000mAh Li-ion batteries, it will run this thing in Rx for 23 hours. That's plenty of operating time.
Tx power and current are about the same for all bands:
5.0W @ 15V, 520mA 65% efficiency
4.25W @ 13.8V, 475mA 65% efficiency
2.75W @ 11V, 400mA 63% efficiency
1.75W @ 9V, 350mA 56% efficiency
1.0W @ 7.5V 300mA 44% efficiency
It looks pretty bullet-proof since it's rated for operating from a 7V - 16V power supply. That's a really wide range. I like that it will operate down to below the voltage of a discharged 3 Li-ion pack (about 7.5V). I get to use the whole pack.
There's so much information in the manual that I can tell I'm going to learn a lot about radio circuit design :D
NEXT KIT TO SHIP
serial number
184
:P
I just finished reading the circuit description in the manual, wow! Hans has really thought this radio out, in fact there are a lot of features for the price. I really like the class E final amp. A couple of years ago I built the NM0S NS-40 CW transmitter which is also class E amp and very efficient, 5 watts out of a IRF-510 that runs cool without a heat sink. I'm kind of surprised Hans didn't one Mosfet vs three of the smaller BS-170's. Anyway, this is going to be a cool radio. Building in the tools to balance the I/Q phase is a nice touch too. All for 51 bucks:-)
Joel
N6ALT
I think backlight is as much as 35mA. There is this suggestion too aside from switch:
QuoteModern LEDs as used in today's LCD displays will provide fairly bright
illumination at currents of 3 to 10 ma. Try using a larger resistance
value in series with the backlight LED. Usually 1K in series with a 5V
or 2.2K with 12 volt source is adequate for both day and night viewing.
Experiment to see what is best for your particular situation.
Also this can be made dual band (not instant switch over, but still...) without too much trouble, here regarding 20/30m:
QuoteYou won't be able to use the band pass filter T1 on either band. It is single band because it is quite sharp (see spectrum analyser traces in the manual). You could probably find a number of turns for the tuned winding of T1, which allowed the trimmer capacitor to tune for either 20m or 30m. Measured tuning ranges are also published in the manual. BUT, it would mean that when you want to change band, you would need to re-peak the BPF each time using the self-alignment menu item "8.7 Peak BPF".
You could build the LPF for 20m and operate 30m into it but you may not achieve adequate harmonic suppression on 30m band.
The Class-E resonant circuit is quite broad and you could find a compromise-value, it would probably result in a little loss of efficiency and power, but may be acceptable.
QuoteI'm kind of surprised Hans didn't one Mosfet vs three of the smaller BS-170's.
Steve Weber uses the same scheme for his MTR series. I bet that's where he got the idea...
Gil.
NEXT KIT TO SHIP - Still
serial number
184
No change in 4 days :P
These are being shipped from China so I wonder what the situation there is. If your number is 493+ then that's in the second batch which is allegedly in 2 weeks time. How many are in that batch? One would hope 500 otherwise we're in trouble.
The rate at first was averaging 10 sent out per day, but that was a small time sample so no good indication of longer term. If it is, and now it has dropped way below that average, we won't get our QCX this year. So they certainly need large quantities AND full time sending out, which I don't know how that can be afforded easily even in China.
I think the better option if they can arrange it, is to have this done across the border in Laos. The postage is crazy cheap, and the cost of living is less. That's how some of the Pixies are sent out.
Sparks and all,
QRP Labs was on Yahoo groups, but has move the group to https://groups.io/g/QRPLabs
Good move in my opinion.
Joel
N6ALT
I got the email that my kit shipped yesterday(http://i120.photobucket.com/albums/o170/cockpitbob/Emoticons/party_zps2d69794f.gif) (http://i120.photobucket.com/albums/o170/cockpitbob/Emoticons/party_zps2d69794f.gif)
The email asks that I email them when it arrives so they can track shipping time statistics. I like these guys.
NEXT KIT TO SHIP
serial number
318
Quote from: swxx on September 01, 2017, 08:58:29 PM
These are being shipped from China so I wonder what the situation there is. If your number is 493+ then that's in the second batch which is allegedly in 2 weeks time. How many are in that batch? One would hope 500 otherwise we're in trouble.
The rate at first was averaging 10 sent out per day, but that was a small time sample so no good indication of longer term. If it is, and now it has dropped way below that average, we won't get our QCX this year. So they certainly need large quantities AND full time sending out, which I don't know how that can be afforded easily even in China.
I think the better option if they can arrange it, is to have this done across the border in Laos. The postage is crazy cheap, and the cost of living is less. That's how some of the Pixies are sent out.
Actually, they are being shipped from Tokyo Japan.
Joel
N6ALT
Mine shipped too but nothing so far...
Gil
Sent from my SM-G928F using Tapatalk
Mine is going to be a while, number 628.
Joel
N6ALT
Christmas... 2019...
Gil
Sent from my SM-G928F using Tapatalk
I just got a box from Tokyo 8) 8) 8) 8) 8) 8) 8)
Lately I've been working my a$$ off nights and weekends. I think I'll take some time for myself this weekend and build it (even though I have an un-built Frog Sounds and a Pixie that needs debugging.)
NEXT KIT TO SHIP
serial number
506
Congratulations Bob,
I hope you enjoy building it. Mine will be awhile yet, but that's okay I'm in no hurry. I think I'm going to mount the display and all controls off board so I can put it in a nice case later.
Joel
N6ALT
Anyone already have plans for the enclosure? I signed up for the QRP-labs group(like a yahoo group) and someone there found a metal enclosure that's a perfect fit. There's pic in the link below, but I'm not sure you can see it without joining.
https://groups.io/g/QRPLabs/topic/qcx_perfect_encosure/6080634?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,6080634 (https://groups.io/g/QRPLabs/topic/qcx_perfect_encosure/6080634?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,6080634)
Here's the link to the box: $11.46 shipped from China
http://www.ebay.com/itm/Split-body-Extruded-Aluminum-Box-Enclosure-Case-Project-electronic-DIY-110-88-38/380955959898?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D45728%26meid%3D43bf45d8db544dbaa54e6904f2953a22%26pid%3D100005%26rk%3D1%26rkt%3D6%26mehot%3Dpp%26sd%3D171357381954&_trksid=p2047675.c100005.m1851 (http://www.ebay.com/itm/Split-body-Extruded-Aluminum-Box-Enclosure-Case-Project-electronic-DIY-110-88-38/380955959898?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D45728%26meid%3D43bf45d8db544dbaa54e6904f2953a22%26pid%3D100005%26rk%3D1%26rkt%3D6%26mehot%3Dpp%26sd%3D171357381954&_trksid=p2047675.c100005.m1851)
I'm toying with the idea of designing a 3D printed box. It won't be metal/shielded, but it will be lighter and I can incorporate a battery compartment or make room for an EFHW coupler. I also don't feel like trying to put a neat, perfectly square hole for the display in an extruded box or fuss with getting the length of a bunch of standoffs just right :P OTOH, I've found 3D designing an enclosure is very time consuming and tedious (at least for me ::))
Thanks Bob! I still don't have mine. It's been 25 days since shipping...
Gil.
Soon
OK. After reading through this topic, I have placed an order for the QRP Labs 5W CW Transceiver kit. Today.
I just had to join in the fun.
I am new to this site and fairly new to the hobby, licensed in 2014. However I did build my first 80 m radio transmitter in. 1968 !!! It took till I retired to find the time to study and pass the Exams. Now a full UK Licence holder and holder of a French callsign as I have retired to France.
My radios include a Kx1, a K2 , and MTR 5 B , all for QRP Operation in the field.
As a longtime Scout, I have long interest in Survival and Prepping Subjects with radio being the latest addition to the skills levels acquired.
73 Steve
Hi Steve, and WELCOME aboard the board! ;D
That's a great selection of radios you have. The only thing missing is a Pixie, 49er or Frog Sounds so you can claim you've made HF contacts on a radio you built for less than $20 ::)
Hi
Done that !!! Sir,
Cant say it was a big success however
Hi Steve, where are you located in France?
My kit was returned to Japan! Sent again a couple days ago... Now I have to wait another two weeks! :(
Gil.
Quote from: gil on October 20, 2017, 11:31:05 AM
My kit was returned to Japan! Sent again a couple days ago... Now I have to wait another two weeks! :(
Gil.
Nuts! Sorry to hear that. It seems they have a problem with their supplier's shipping. Not the first time this has happened, I believe.
Quote from: cockpitbob on October 20, 2017, 01:52:43 PM
Quote from: gil on October 20, 2017, 11:31:05 AM
My kit was returned to Japan! Sent again a couple days ago... Now I have to wait another two weeks! :(
Gil.
Nuts! Sorry to hear that. It seems they have a problem with their supplier's shipping. Not the first time this has happened, I believe.
Right... They probably sold a thousand... I hope I get it... You'd think the Japanese would be efficient... Seems like China is getting ahead for shipping reliability...
Gil
Sent from my SM-G928F using Tapatalk
Hi,
Sorry to hear that Gil about the delivery problems, at least you will not be too far ahead of me in the build timming !!!
I need to wait till middle of November I think before mine. is shipped, then plus two/three weeks before arrival.
I live about 40 miles inland of La Rochelle , near Vovent 85120
I was hoping eventually that we make contact on the airwaves, a perfect distance for trialing regional distance comms.
I have much in common with you I think ( Flying , sailing, radio, ) so it may be some time before we run out of things to chat about !!!
Check out QRZ.COM M0ZSM for a short bio
Steve
QuoteI was hoping eventually that we make contact on the airwaves, a perfect distance for trialing regional distance comms.
Definitely, I'll let you know when I get a more permanent setup...
Gil.
My QCX showed up this morning, YAAAAA! Now to find some uninterrupted time to build it. Probably start on it Mon morning after my wife goes to work and all is quiet. I noticed it came with the 1.00b firmware, so First thing after building it will be to attempt to upgrade to 100.c.
Joel
N6ALT
One more thing, are any of you guys going to use IC sockets or just solder the chips? I have some good quality machined pin sockets, but I don't want to introduce any problems either. I have never experienced any problems using sockets, but there is always the first time. Your opinions matter.
Joel
N6ALT
Mine (which I still haven't started assembling) also came with 1.00b firmware. I think I've got a spare Arduino Uno kicking around somewhere from when the boys were doing that in high school.
I'm on the fence for sockets. I usually use them because they make me feel good knowing I can swap out a chip, and I've never had a problem using sockets. On the other hand I can't count the years since I've had to replace a chip on something like this. For this kit I think it will depend on my mood ::)
I bought a EFE 40 on eBay, it's a 40 meter SSB QRP rig. It came with all the chips in sockets and completely preassembled, board only. It worked great for a couple of hours and then went dead on receive. It turns out that one of the 4 NE602, (yes 4!), mixer chips went belly up. I just popped it out and stuck another one out of my drawer and I was back on the air. It ran for years until I decided to clean out the shack and I sold it for 40 bucks more than I paid for it mounted in a nice black case. I could have sucked the chip off the board, but wasn't sure whether is was the culprit or not, so it sure made trouble shooting the problem easier. Still, I don't know whether I want to do it on the QCX or not.
Joel
N6ALT
Well, I'm 2/3 through the QCX build and decided not to use IC sockets, hope it all works.
Joel
N6ALT
Quote from: caulktel on October 23, 2017, 06:40:52 PM
Well, I'm 2/3 through the QCX build and decided not to use IC sockets, hope it all works.
Joel
N6ALT
I am not going to use sockets either... Just ordered the enclosure mentioned above from Ebay, We'll see...
Gil
Sent from my SM-G928F using Tapatalk
I got my kit this morning, well, late morning, and it's almost finished... Except that C17 is missing! >:(
Winding the 68 turns (for 80m) then 3x5T for T1 was a pain. It could have been explained a little better. Other than that the manual is great. I hope I can find a 39nF capacitor somewhere.. I am not the only one, another YouTuber had the same problem, same component I think.
(http://radiopreppers.com/images/QCX-T1.jpg)
Messy... I hope it works...
Gil.
Gil, that looks great. I'm jealous! Can't wait to hear your operating reports.
Finished!
It works without C17... I will test it later, but output is 5+W, everything works, amazing little radio for $49!
Gil.
Looks great Gil, I finished mine a few minutes ago but haven't done the alignment yet. I does work and I can hear many QSOs going on on 20 meters. That T1 was a bear alright, but I got it wound and installed. Sorry about your missing parts, that's a bummer. Here's mine.
Joel
N6ALT
Well done Gil, can't wait to hear your reports on the workings of the radio. Mine is serial number 1668 and should be sent mid November. Excited
Steve
QuoteThat T1 was a bear alright, but I got it wound and installed. Sorry about your missing parts, that's a bummer. Here's mine.
Good work Joel, your T1 looks much better than mine but no way 68 turns was going to look good.
Now I need to put up that 8010P end-fed on the roof...
QuoteMine is serial number 1668 and should be sent mid November. Excited
Which band Steve?
Gil.
I finished the alignment this morning and I was impressed at how simple it was. I have been copying quite a bit of activity on the 20 meter band. The power output seems a tad low though, 1.6 watts at 13.8 V and 1.4 watts at 12.8 V. Maybe that is all to be expected at 14Mhz. Anyway 1.5 watts is plenty to communicate with.
Joel
N6ALT
Just updated the 1.00b firmware to 1.00c using a Arduino ICSP made out of one of my many Arduino UNO clones. Worked great. I'm having a blast with this radio. Got to figure out how to install in a enclosure next.
Joel
N6ALT
I just ordered an AVR programmer, super cheap on Ebay:
https://www.ebay.com/itm/USBTiny-USBtinyISP-AVR-ISP-programmer-for-Arduino-bootloader-Meag2560-uno-r3/400368767664 (https://www.ebay.com/itm/USBTiny-USBtinyISP-AVR-ISP-programmer-for-Arduino-bootloader-Meag2560-uno-r3/400368767664)
Unfortunately, the missing C17 has to be 39nF, so Hans is sending me one.. :(
This postpones my video unfortunately, but then I will be able to add a bit on upgrading the firmware.
Gil.
Quote from: gil on October 25, 2017, 08:27:02 AM
QuoteThat T1 was a bear alright, but I got it wound and installed. Sorry about your missing parts, that's a bummer. Here's mine.
Good work Joel, your T1 looks much better than mine but no way 68 turns was going to look good.
Now I need to put up that 8010P end-fed on the roof...
QuoteMine is serial number 1668 and should be sent mid November. Excited
Which band Steve? Mine will be for 80 metres
Gil.
Hello Gil
Mine will be for 80 metrs
Need to work out a decent antenna for 80 , while I wait for the radio,
Did have a dipole, but that was not very successful.
So will try with an end fed, and use my ZM 2 atu to begin with
73 Steve
Quote from: Steve 7931 on October 26, 2017, 07:01:43 AM
Hello Gil
Mine will be for 80 metrs
Need to work out a decent antenna for 80 , while I wait for the radio,
Did have a dipole, but that was not very successful.
So will try with an end fed, and use my ZM 2 atu to begin with
73 Steve
A W3EDP would work great with the ZM-2...
Gil
Sent from my SM-G928F using Tapatalk
Gil
W3 EDP not known to me. So will research and let you know
Steve
Gil
Liked what I found, I have ordered one from Moonraker in the UK just now, so will take a week or so to get here.
Will try it out with my FT 817. And report back here. Thanks for the recommendation.
Also the little speakers, Veho 360 arrived and working out fine wid the MTR 5 B. Thanks
Steve
Quote from: Steve 7931 on October 26, 2017, 07:28:07 AM
Gil
Liked what I found, I have ordered one from Moonraker in the UK just now, so will take a week or so to get here.
Will try it out with my FT 817. And report back here. Thanks for the recommendation.
Also the little speakers, Veho 360 arrived and working out fine wid the MTR 5 B. Thanks
Steve
Great. 17ft of ladder line plus 67ft of wire is all you need for a W3EDP...
Gil
Sent from my SM-G928F using Tapatalk
Quote from: gil on October 26, 2017, 04:35:48 AM
I just ordered an AVR programmer, super cheap on Ebay:
https://www.ebay.com/itm/USBTiny-USBtinyISP-AVR-ISP-programmer-for-Arduino-bootloader-Meag2560-uno-r3/400368767664 (https://www.ebay.com/itm/USBTiny-USBtinyISP-AVR-ISP-programmer-for-Arduino-bootloader-Meag2560-uno-r3/400368767664)
Unfortunately, the missing C17 has to be 39nF, so Hans is sending me one.. :(
This postpones my video unfortunately, but then I will be able to add a bit on upgrading the firmware.
Gil.
Hi Gil,
I have that exact programmer, however I could never find it in AVRDudess or I should say AVRDudess never found it, that's why I ended up using a Arduino with a serial port. Everybody on the QRPLabs group is telling me it should have worked, maybe it will for you. It seems that my low power output is because of the output LPF caps, so now I have to find some higher voltage caps that will fit in the existing holes on the board. I'm not really happy about this, the right caps should have been included in the kit. I think I will concentrate on putting it in a enclosure while Hans figures out the bugs. I hope you get your cap soon.
Joel
N6ALT
Quote from: caulktel on October 26, 2017, 09:38:34 AM
It seems that my low power output is because of the output LPF caps, so now I have to find some higher voltage caps that will fit in the existing holes on the board. I'm not really happy about this, the right caps should have been included in the kit.
Hi Joel, Which caps are those?
Gil
Gil, they are C25-C28. In my case they are 2ea 390pf and 2ea 180pf. Apparently the ones provided are not high enough voltage rating and are heating up during Zmit and are responsible for low power output. I'm not sure I agree with this theory, because they are 50 volt caps and I have used them up to 7-8 watts without any trouble. I think somebody is grasping at straws. In any case a lot of people are having the 1.6 watt output problem and Hans needs to get to the bottom of it.
Joel
N6ALT
QuoteIn any case a lot of people are having the 1.6 watt output problem and Hans needs to get to the bottom of it.
Darn, I hope I don't have that issue... We'll see. I wonder if Hans got the idea of using three BS-170 transistors as finals like Steve Weber does for his MTRs... Why reinvent the wheel... Steve has no trouble getting 5-6W out of those little guys though...
Gil.
Quote from: caulktel on October 26, 2017, 12:46:23 PM
Gil, they are C25-C28. In my case they are 2ea 390pf and 2ea 180pf. Apparently the ones provided are not high enough voltage rating and are heating up during Zmit and are responsible for low power output. I'm not sure I agree with this theory, because they are 50 volt caps and I have used them up to 7-8 watts without any trouble. I think somebody is grasping at straws. In any case a lot of people are having the 1.6 watt output problem and Hans needs to get to the bottom of it.
Joel
N6ALT
I too doubt it's the voltage. If they are heating up it's their ESR (equivalent series resistance). There's a lot of AC current flowing through the Tx filter capacitors.
ESR is determined by the dielectric used. From good to bad, the common dielectrics are:
NPO and Mica: Either is the good stuff. Almost zero ESR. Very stable(doesn't drift with time, temperature, voltage). Can't get them in large values though.
X7R: Most commonly used. ESR 25 times greater than NPO. Used when 2nd best is fine.
X5R: Same as X7R but not quite as stable.
Y5U: Cheap stuff, but you can get large values in a small package. ESR 2X worse than X7R. Changes value like crazy: temperature, frequency, DC voltage. Put 48V on a 50V capacitor and its capacitance goes down by 80%. Seriously, a 1u cap becomes 0.2u.
For a Tx filter I would NEVER use anything but NPO or mica capacitors.
EDIT: I just looked at my 80M filter bag and I can't tell what type of capacitors are in there. I guess if my power is low I'll just swap all of them with NPO caps
I got my QCX yesterday.Three and one half hours later it was up and running on 40 meters. Impressed with the features too. I was missing a 10uf capacitor but I had tons in stock. Couple of notes:
1) Backlight brightness a little too bright. Maybe okay for daylight use. The 270 ohm resistor on pin 15 of the display could be raised to 4.7k or a 10k pot/switch could be added. Current drain reduced from 120 ma to 93 ma. Still sufficient for daytime use.
2) Had to move the L6 choke so the processor would not lock up on powerup. (according to their mods page)
3) For 40 and 80 meters the T1 toroid is a little hard to wind without messing up the turns and getting all the secondaries lined up. I found that some fingernail polish on the windings will hold the turns in place while winding and mounting. I also used tweezers to carefully push wires into the proper pads. Just don't forget to strip leads sufficiently.
I haven't had a chance to check the transmitter section for purity and modification suggested by the website mods page.
All in all, a great little addition to my collection.
Rick
Hello. I just ordered a 30m QCX. Also updated the firmware on mine to 1.00e using an Arduino Uno and the PDF file I will attach here. This fixed a slight keyer issue which forced you to be very quick on dits or you would get a dah. All is fine now. I tried the WSPR feature and got an interesting map of my antenna efficiency. Lots of regional spots and a few up north, not surprising given that my antenna is only about 20ft up. I also has a nice QSO with Martin G0PJO who to my surprise told me he watched my videos since one of his friends was in my "Morse Code en Provence video!" He has a QCX on 30m but was using a KX3 if I got it right.. It's nice to have a real chat once in a while. All these 559-73 contacts have not helped my practice...
(http://radiopreppers.com/images/QCX-WSPR-80m.png)
This was only two calls!
Gil.
I decided to go with Hammond 1590BB cases for my 80m QCX and upcoming 30m model:
(http://keskydee.com/images/QCXcases.jpg)
Those cases are Chinese knock-offs... I should have been weary of the low price...
Not finished yet... I am waiting for the buttons to arrive.
The PCBs will be bolted to the lids via 20mm spacers.
Gil.
Finished!
(http://keskydee.com/images/QCXa.jpg)
Retrofitting was not fun. The next one will be much easier, nothing to de-solder!
(http://keskydee.com/images/QCXb.jpg)
Everything is bolted to the cover.
(http://keskydee.com/images/QCXc.jpg)
Note the power connector; not the best place but there was no space left anywhere else.
The 1590BB is a perfect case for the QCX.
Everything works! This will be a great field radio. 80m has won my approval these last couple years... I thought contacts on 80m CW at QRP levels would be difficult... Boy was I wrong!
Gil.
I am having a blast with the QCX on 80m! At last, I can get some rag-chew time :) 80m seems to be the only band on which people are willing to chat around here. Coverage is very good with my 8010P end-fed. Someone told me the QCX outputs 2.5-3W... I don't know, but if I output 3W, it sure gets around! That rig is an awesome radio, too bad it burns so much current. Three 18650 cells let me operate for quite a long time though, I have not emptied a pack in one session yet.
I need to experiment with different 80m portable antennas in the field. This band works too well for prepping to avoid because of antenna length.
Gil.
Good start on my 30m QCX...
(http://keskydee.com/images/QCX30pcb.jpg)
Gil.
Hey Gil,
Did you find a good enclosure for your 80 meter rig? I've almost got mine done but I don't want to put on the components that poke out until I settle on a case.
QuoteDid you find a good enclosure for your 80 meter rig?
Yes, Hammond 1590BB, perfect fit! You do need to put the controls off board, except the antenna BNC.
Gil.
Great! Thanks Gil!