Re: 20m QCX RF Output Question
#qcx
I too, probably am getting about 2.5watts output on my QCX20, for more power, I use this to drive my HFpacker QRP linear amp.? My 3-el tri-band Yagi up on the tower, helps a lot too. This combo does an excellent job!? Since my QCX20 is working great, I am not going to fool with it!? 73, Karl, KO8S
On Thursday, March 28, 2019, 04:52:52 PM EDT, KT4RK <Kt4rk.tn@...> wrote:
I went ahead and took off two turns from L1 and L3 and it made no difference at all. I guess I need to keep fiddling with it.
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Re: #qsx Suggestion: Use different antenna for RX and TX
#qsx
I must correct myself: Resistances of a loop are (for example): 0.092 Ohms: Losses in Loop? (14 MHz; ) 3 Ohms: Preamp's differential input resistance (LZ1AQ's article; but this is not comparable to the other resistances: higher value means better SNR) 0.030 Ohms: radiation resistance (14 MHz;) The 0.5 Ohms for losses in loop? in LZ1AQ's article are for a Norton equivalent model, which is not suitable for comparison with radiation resistance. This means: radiation resistance is not so much lower than I originally stated. If the given values on the linked website are correct, on 20 m losses are 3 times as high as the radiation resistance (loop circumference 2.35 m and conductor diameter 8 mm^2) I've now read quite a lot in /g/loopantennas and LZ1AQ's article and my conclusions are: * There are at least 2 good preamp-designs: LZ1AQ and N7ZWY. * N7ZWY's preamp is probably better, for example regarding IMD and noise. * LZ1AQ's design is easier to build and has less ferrits which are possibly difficult to get. * I think I'll start with LZ1AQ's preamp, therefore. * If internal noise of the amplifier is to high for my location, maybe I'll try to increase differential input resistance by a transformer. (I'm only interested in 1.8 to 30 MHz.) 73 Axel DF1ET
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Hello
The problem (QCX # 4174: "select band", sometimes "use original chip") continued to be erratic. My programmer (MySmartUSB light) could not read or write a fuse. Now I found a firmware update tool for the programmer, and I can read / write the fuse.
Result: 2 fuses in the Atmel328P were not set correctly according to the specification qrpLabs:
- The E-Fuse turned off the Brownoutdedektor, which may have been the cause (critical writes to the EEprom with reduced operating voltage when switching off possible).
- The H-fuse did not protect the EEprom from overwriting when programming the flash.
After changing the fuses, the device was switched on / off 50x, no error, even in the previously more sensitive version T1.00.g.hex. This explains the occasional program crashes since the initial commissioning. As a result of the replacement of the mechanical rotary decoder by electronics in my QCX, these writes may have been triggered by the electronics when switched off, so perhaps quite common occurrence.
73 Reiner
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Wow, this site protects one from giving out their email. Normally good. It's jkbaum then @usa.net
Try that.
Jerry
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Sorry, QRZ only gives my street address.? Jerry jkbaum@...
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Daniel,
I have a 2nd QCX 40M which I just built. I tuned it last night and haven't even programmed it. Look me up on QRZ.com - KE0PRQ
Jerry
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Re: Ammo can QCX Antenna testing today. 1st run.
#40m
#qcx
I called cq for about an hour, Just a few skimmers, was hoping some mid-west stations may com back at SR. Going to warm the fingers a bit as its only 40F in the garage, and try some more in a bit.
Steve Raas?
N2JDQ?
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Thank you for the update Hans Doug ?? k6sts
On Friday, March 29, 2019, 08:26:53 AM EDT, Hans Summers <hans.summers@...> wrote:
Hi Dennis, all
Good news... Today we received 1,000 Si5351A Synth PCBs, 3,000 LPF PCBs, 200 ProgRock PCBs and 250 Dummy Load PCBs... ahead of expectations (Monday)... I don't know how exactly, because even this morning XYL telephoned the customs clearance agent to try to get the domestic courier tracking number, and they said they have not yet received the boxes from customs so cannot give us the tracking code until tomorrow. So imagine how surprised I was when the cargo company banged on the door just now and I opened it to find three big boxes waiting! Someone got their wires crossed somewhere... anyway... any orders which are awaiting these kits, we are now packing. Too late today for any more post office missions but they should all be shipped out on Monday and Tuesday.?
73 Hans G0UPL
On Thu, Mar 28, 2019 at 8:31 PM Hans Summers via Groups.Io <hans.summers= [email protected]> wrote: Hi Dennis
The PCBs cleared customs yesterday. It normally takes 3 days to reach us via a domestic courier?service. So Monday we will start shipping out the pending orders.
73 Hans G0UPL? ?
getting curious about delivery time
Dennis
AG4TD
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Hi Dennis, all
Good news... Today we received 1,000 Si5351A Synth PCBs, 3,000 LPF PCBs, 200 ProgRock PCBs and 250 Dummy Load PCBs... ahead of expectations (Monday)... I don't know how exactly, because even this morning XYL telephoned the customs clearance agent to try to get the domestic courier tracking number, and they said they have not yet received the boxes from customs so cannot give us the tracking code until tomorrow. So imagine how surprised I was when the cargo company banged on the door just now and I opened it to find three big boxes waiting! Someone got their wires crossed somewhere... anyway... any orders which are awaiting these kits, we are now packing. Too late today for any more post office missions but they should all be shipped out on Monday and Tuesday.?
73 Hans G0UPL
On Thu, Mar 28, 2019 at 8:31 PM Hans Summers via Groups.Io <hans.summers= [email protected]> wrote: Hi Dennis
The PCBs cleared customs yesterday. It normally takes 3 days to reach us via a domestic courier?service. So Monday we will start shipping out the pending orders.
73 Hans G0UPL? ?
getting curious about delivery time
Dennis
AG4TD
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Re: Ammo can QCX Antenna testing today. 1st run.
#40m
#qcx
I woke early and set back up in the garage, I seem to have a little noise around 7.030...so I may cq a bit lower. I'll be watching RUN to ensure I have a clear QRG .. I should be on by 725am. Just warming the fingers a bit.
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Re: WSPR with the QCX - getting the time right
#wspr
#160m
First of all - thank you Andy and Curt.
And now the great news:? wsprnet picked up my signal last night!? So now I know it is working.? I hit three stations - one in Europe and two in California.? Wow.??
I am using an old computer laptop battery as the power source, and my trap vertical as the antenna.? The battery has lasted all night, so I am confident that the battery would be a good candidate for power source on any one-day hikes or SOTA activations.? Looking good!
73, Joe
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Re: Final assembly of 10w amplifier kit
I mentioned this last October.? My PCB was down as far on the legs of the FET's as possible.? I just turned up a spacer to even the height. A suitable washer under the nut would work also.
glenn
vk3pe
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Re: WSPR with the QCX - getting the time right
#wspr
#160m
Wspr needs to tx on a 2 minute slot.
The slots MUST be at either 2,4,6,8 etc mins past the hour. You CANNOT have a
tranmision starting on a 1,3,5,7 mins
past the hour.
73 de Andy
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Re: WSPR with the QCX - getting the time right
#wspr
#160m
Set the time on QCX to WWV.? The QCX displays the time to the second, and it is set to within a half second to WWV.? Good enouf.
About the frequency, I set the 40 meter QCX WSPR frequency to 7.04096 which is very close to the middle of the 200 hz band.? Should be good enough but I can't really tell how good the display frequency is with respect to wspr.?
I think that I have everything set up correctly, 10 minutes span, frequency, time is set, my call and grid and power is set to 33.? But I am still waiting to see my call on wsprnet.com? ?Is there some way to check the correct frequency display???
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Re: Final assembly of 10w amplifier kit
Re the IRF510s full through the board?? The face or the irf510 should be almost
flush to the board.? If you have leads or other things in the way that can't happen.
I've built 4 not something I've seen.
Allison
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Re: Final assembly of 10w amplifier kit
Just checked mine and it is about 5mm at both ends of the board
give so your problem is at input end of board. This is the end
where the spacer nut is. Check thickness of nut, it is specified
in the parts list as being 4.4 mm thick so you are 1mm out. The
electrons won't mind going uphill but you may run the risk of
physically stressing the board.
On 3/28/2019 7:38 PM, Charles W. Powell
via Groups.Io wrote:
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I have completed all but the final assembly of the 10w PA board.
?I put the IRF510 FETs on the heat sink and put everything else in
place. ?The PCB does not sit level above the heat sink, even with
the large nut in place. ?On the IRF510 side the board is 5mm above
the heat sink. ?At the other end it's 3.5 to 4mm. ?
So here's the question: Is this what others have seen? ?Do I need
a shim to level out the board? ?Any suggestions on what to use as
a shim? Does it really matter?
72,
Charles - NK8O
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Re: Balloon and similar payload electronics and conformal coating
Good advice Doug, thank you.
cheers, Graham ve3gtc
On 3/28/2019 11:14, k6sts via Groups.Io
wrote:
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Regarding conformal coatings, keep in mind that all the Max
GPS series modules I am aware of are NOT hermitically sealed.
They have a warranty period and some can be repaired. Usually
for the way we use them being unrecoverable, the warranty is
not an issue, but if you spray something on the module and it
gets inside through the tiny holes surrounding the top cover
is can cause the module to have problems.
Ublox specifically states in the datasheet not to conformal
coat the module
If you choose to conformal coat the PCB, mask off the Ublox
first.
Regardless of the components you use, it's a good idea to
read and understand? the individual datasheets of the
components to avoid simple issues like this.
In my experience, just because you unknowingly got away
with something and it worked, doesn't mean you did everything
wright. Just my 2 cents worth.
Doug ?? k6sts
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Re: 20m QCX RF Output Question
#qcx
I went ahead and took off two turns from L1 and L3 and it made no difference at all. I guess I need to keep fiddling with it.
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Re: 20m QCX RF Output Question
#qcx
I removed 1 turn each and got about an additional 500mw.
73 Vince N1VIN
On 3/28/2019 1:50 PM, KT4RK wrote:
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Hi all. I just finished my first QCX build for 20m and I’m curious
about the power output. I’m currently getting around 2.5 watts RF
output based on the readings provided by the QCX menu 9.2. After
reading some other threads, it seems it’s possible to increase the
power output by removing turns from the L1, L2, and L3 toroids. My
question is: what sort of increase I should expect? I’m trying to
decide if it’s worth the trouble to do the modification if I’m
only going to get a few mW difference. Any other suggestions are
appreciated.?
de KT4RK?
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Re: Final assembly of 10w amplifier kit
Just checked mine and the PC board is the same distance from the heat sink on both ends. On the FETs did you did you bend the leads right where they leave the body or at the standoff step down on the leads?
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Joe Cotton
KT4RK
N3MNT