Date   

Re: Build Time

Hans Summers
 

Hi Lou

Producing kits is already hard enough and i had always thought I'd avoid being a component distributor too, which is 10x more difficult unless you're an enormous business like Digikey etc. 

I also don't have tons of stock of all the parts we use and it would be expensive and complex to stock them just for the occasional potential sale. What I've done so far is stock some things which are custom parts not easily obtainable elsewhere. Not things like resistors which can be found anywhere. 

Anyway I will give it some further thought, thanks for the suggestion.

73 Hans G0UPL 

On Mon, Jun 14, 2021, 12:00 VK5EEE <vk5eee@...> wrote:
PS further to my last, I see components (a few) ARE available on site, would be nice to have them ALL available subject to order surcharge if nothing else ordered? E.g. for replacements or mods such as filter bandwidth, etc.

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Re: #QCX+ D3 MOD - D3 replacement for LOW voltage drop

Jim Campbell
 

Some 60 years ago I was a young engineer and ham. Semiconductors were in a very basic form, diodes and NPN and PNP transistors. Our solutions back then tended to be very simple.

This afternoon I gave some thought to to the problem of voltage drop due to an inline diode. Why can't we get a small SPST relay and put a diode in series with the coil. Then wire the +12 volts through the SPST contacts. If the polarity of the input was correct the relay would pick and the full 12 volts would be applied to the radio. What am I missing?

73,

Jim Campbell
W4BQP since 1953


Re: QCX WARC Party

John Pagett G4YTJ
 

Two QSOs on 30m in the 1900z session tonight, running about 4 Watts from an original QCX.
Zdenek OK2BQN with a QCX, and Harry DL6LV (Not QCX)

Luc was too weak to copy, as was IW2HTH.

John
G4YTJ


Re: Standard Si5351A module kit fitted with QCX+ tcxo?

Hans Summers
 

Hi Mont

Did you keep the original TCXO pads on the Si5351 Synth Board?  (I hope I hope).

Yes, the original TCXO pads are still present. The crystal and 0.1uF capacitor were simply moved slightly to line everything up so that the QRP Labs TCXO module can be installed on top - exactly as it does on the QCX+ 

While I'm at it, any chance of getting the 4 TCXO pads added to the QCX/QSX line, to give experimenters more options?

I haven't considered that. When you have something that works as well as QCX+/QCX-mini, interfering with that requires a stronger motivation... 

73 Hans G0UPL 


Re: Benefit in following WSPR band hopping schedule? #u3s

Sverre Holm
 

I should add that the recommended band hopping sequence is from low to high frequency: 160m, 80m, ..., 10m (10 bands). This is the opposite order of what used to be recommended for the U3S for maximum stability which was high frequency to low.

However, after I fitted the 25 MHz TXCO to the U3S, the order is no longer important as it is stable enough regardless of order. (https://la3za.blogspot.com/2021/03/qrplabs-25-mhz-tcxo-doing-good-in-u3s.html)


--
Sverre

 

LA3ZA, http://la3za.blogspot.com


Re: tuning without detents

Hans Summers
 

Hi Jerry

Huff & Puff is the reason why I had a website, in 1999... I set it up to publish a library of all the interesting articles on H&P that I could find. Everything since, grew from that moment. See http://hanssummers.com/huffpuff

73 Hans G0UPL
http://qrp-labs.com 

On Mon, Jun 14, 2021 at 10:00 PM jerry@... <jerry@...> wrote:
On 2021-06-14 08:47, Johan Bodin wrote:

>
> I used it on two QRP rigs, one with varicap tuned VFO and a
> huff'n'puff stabiliser and another rig with AD9835 DDS VFO.

*** Huff'n'puff?  Whazzat?  (google-google-google).  Ohhhh.  Sounds like
just the thing to stabilize my small collection of SB-34 transceivers.

    I did something similar back in the late 70's.  Had a Pertec floppy
drive on my TRS-80 computer.  It would work well in the morning and
start making errors in the afternoon.  It was due to the motor speed
drifting.  The motor was controlled by a one-shot with a multi-turn pot
feeding into a zero-voltage node on an opamp.  And the cap on that
one-shot would drift with temperature.

    I built a stabilizer with a crystal oscillator and dividers producing
IIRC 200Hz, which matched the frequency of the optical speed sensor on
the disk.  Put the two signals into an XOR gate, filtered the output
with a resistor and a cap, and produced a small/slow current error
signal that fed into that zero node on the motor control opamp.  After
that, the Pertec was supernaturally stable.

                     - Jerry KF6VB







Re: QCX WARC Party

Peter GM0EUL
 

I was on for the 1300z session with my 20m QCX re-set for 30m and working pretty well, putting out about 3 or 4 watts to a dipole.  I had a couple of nice and quite long qsos first with John, G3SZG near Worcester running an ic7300.  Then Dave M3PMG in Hull also running a QCX.  Decent signals both ways, I'm pleasantly surprised at how well the 20m QCX works on 30m.

73 

Peter GM0EUL

CWops 1899. FISTS 18888, SKCC 16307T, GQRP 15056



On Mon, 14 Jun 2021 at 15:52, Zdenek OK2BQN <ok2bqn@...> wrote:
Hi Daniel,
the conditions were very bad. We probably wouldn't hear.
73
Zdenek


Re: tuning without detents

jerry@tr2.com
 

On 2021-06-14 08:47, Johan Bodin wrote:

I used it on two QRP rigs, one with varicap tuned VFO and a
huff'n'puff stabiliser and another rig with AD9835 DDS VFO.
*** Huff'n'puff? Whazzat? (google-google-google). Ohhhh. Sounds like just the thing to stabilize my small collection of SB-34 transceivers.

I did something similar back in the late 70's. Had a Pertec floppy drive on my TRS-80 computer. It would work well in the morning and start making errors in the afternoon. It was due to the motor speed drifting. The motor was controlled by a one-shot with a multi-turn pot feeding into a zero-voltage node on an opamp. And the cap on that
one-shot would drift with temperature.

I built a stabilizer with a crystal oscillator and dividers producing IIRC 200Hz, which matched the frequency of the optical speed sensor on the disk. Put the two signals into an XOR gate, filtered the output with a resistor and a cap, and produced a small/slow current error signal that fed into that zero node on the motor control opamp. After that, the Pertec was supernaturally stable.

- Jerry KF6VB


Re: QLG2 and QCX mini time display quirk

Arv Evans <arvid.evans@...>
 

Hans

It is tempting to automate the time before first WSPR, but maybe a 
simpler approach would be to add a user configurable delay(time) 
command to the menu so the user could control delay for any 
function.

Arv
_._


On Mon, Jun 14, 2021 at 5:45 AM Hans Summers <hans.summers@...> wrote:
Hi Ken

GPS does indeed get checked at the end of each WSPR transmission. When beacon mode is enabled it therefore transmits one cycle before it gets to the time setting part...

This is a known issue and on my list :-/

73 Hans G0UPL 

On Mon, Jun 14, 2021, 14:03 KEN G4APB via groups.io <lfoofui.nbz42=ntlworld.com@groups.io> wrote:
I have fitted a super cap to my QLG2 and time is displayed on its own display instantly after switch on, great. But, when connected to my QCX mini, in WSPR beacon mode, the time does not update on the QCX until it has (incorrectly) run a transmission at time 00:00:00 plus FRAME. However, if I back out of beacon mode, in RX mode, the time updates instantly. The problem is, if I want the QLG2 to set the time in WSPR beacon mode, from switch on, I have to back out of beacon mode, let the QLG2 set the time in Rx mode, the pull out the jack plug to the gps/paddle input ( it stops me getting into Preset menu if connected), select beacon mode from the Preset menu, and plug the gps jack back in.
As I am experimenting with battery packs, quite often my QCX resets at the end of a WSPR transmission and looses the time setting, so I cannot just leave it running.
Any idea of an easier method to get the time to set before WSPR beacon transmission?
73 Ken G4apb 


Re: housing for GPS ReceiverOLG1

N3MNT
 

send me an email


Re: housing for GPS ReceiverOLG1

John Sharman
 

is it possible to purchase one as i do not have access to 3d printer

On 14 Jun 2021, at 18:55, N3MNT <bob@...> wrote:

This is a nice 3D printed case;  https://www.thingiverse.com/thing:3582966


Re: housing for GPS ReceiverOLG1

N3MNT
 

This is a nice 3D printed case;  https://www.thingiverse.com/thing:3582966


housing for GPS ReceiverOLG1

John Sharman
 

Does anyone know of a abs housing suitable for the above?

Regards

John


Re: #QCX+ D3 MOD - D3 replacement for LOW voltage drop

 

Had same experience with noise from a modern power meter which they can read from the street without coming to the house. Will we next pick up the magnetic people who've been GMI'd? I don't think the power company will do anything, but be interested what they say if you do try. They'll likely measure it and find it "within specs".

On 14 Jun 2021, at 16:53, Jim Painter via groups.io <Jfpainter@...> wrote:

Skip, check with the power company. If the noise is coming from their equipment, they are probably responsible for fixing it.

Jim….KQ3S
On Jun 14, 2021, at 12:00 PM, Skip Davis via groups.io <skipnc9o@...> wrote:

David this is so true, I took my KX3 and portable HF whip antenna to my new under construction home and was elated to find the noise level only about S1 or 2. I was standing in the room that was to be my future ham shack. After moving in and setting up my station the noise level was S7, so with KX3 and portable antenna in hand I started investigating the sources of noise around the house. To my surprise the biggest culprit is the wide band noise from the power meter and all conduit into the meter and to the power panel up here is plastic.
I was able to reduce some of the noise by upping the size of the grounding cable but could never get ride of it totally. I run most of my station off a battery system and turn on the charger when not operating, so when I’ve had power outages it goes quite again. Even running my generator the noise is half of what is seen from the power company.
Sorry for the off topic to everyone else but this might help others to find that elusive noise they are trying to track down because pulling the main breaker doesn’t eliminate the meter from the equation.

Skip Davis, NC9O








--
Love 30m and CW?
http://www.30cw.net


UFB Dummy Load Kit

 

Am I pleased with this dummy load or what? :-)

I know it is probably one of the simplest things you can get from QRP Labs but since I've not had a dummy load in ages, and over my time have usually not had one, I thought it high time especially building QCX kits and the low price. Ingenuity in how it is designed too. And very robust, unlike what it looks like.

I've learned lots from building it, and here's my results, and what it might do for others who may not have a dummy load. I'm sure I'm not the only poor electronician or real "amateur amateur" in the room :-)

First, the contruction, I actually missed a step as the instructions are not so long and given the simplicity I did not check everything 3 or 4 times, but only once or twice! I missed the jumper BEFORE putting the two boards together but that's no problem, it was easy to insert, and I knew from a first reading that there were two jumpers, so when I got to the "final" one I knew I'd missed the first one.

Also I thought I'd be an idiot and actually try to line up all the resistors instead of using the clever solution. No doubt the harder way but I wanted the fun, and managed without too much difficulty. But next time, I'd do it the recommended easy way. I just wanted to see how hard it is.

Now my test results on QCX mini for 20m (RX not yet working but TX works) and this educated me quite a lot, I did not know that one could measure power, all things being equal or correct rather, with a DVM. So it was interesting to compare the results with my Diamond PWR-SWR analogue meter, on QRP setting where full scale is 30W and each one watt there is a marker. 

The QCX mini was built for 20m, some more adjustments of LPF would likely increase power further, here is what I got at 12V comparing QRP Labs Dummy Load "and DVM Watt Meter" with the Diamond one:

7.020 MHz : 23.5V (5.52W) cf 3.1W
10.12 MHz : 18.15V (3.29W) cf 3.3W
13.77 MHz : 15.29V (2.33W) cf 2.4W
14.02 MHz : 14.10V (1.98W) cf 2W
14.32 MHz : 12.45V (1.55W) cf 1.6W
15.00 MHz : 8.22V (0.69W) cf 0.4W

Two interesting things here, and of course we don't know really how accurate either the "dummy load meter" or the diamond meter are, but the former shows a clear pattern of decreasing power with increasing frequency as expecte, but the diamond commercial meter shows an anomaly at 7 MHz of lower power, and I'm inclined to think this is wrong, but at a loss why at one band it is very inaccurate, but at others aligns very closely to the measurements with dvm. 

Another is that the QCX (mini) puts out good power on a wide range of frequencies in this case tested from 7 to 15 MHz. 

Now I should really compare to the internal watt meter reading making a probe, perhaps I'll do that too as that'd be interesting to compare all 3 results though I guess it'd align with the "dummy load" readings.

Absolutely no deflection of reflected power at the diamond SWR meter so the dummy load is working very nicely. 

A very easy project, very inexpensive, and a must have for QRP ham stations -- or ANY ham station! Now I look a lot less bad, finally having a dummy load and finding uses for it.







--
Love 30m and CW?
http://www.30cw.net


Re: QCX Mini Poor Reception

Mitchel Sayare
 

Hoping someone can help me with this. Cannot figure out why BPF peaks at 6 on my new QCX mini 20 meters. See bias voltages. Many thanks in advance. Mitch NK3H


Re: #QCX+ D3 MOD - D3 replacement for LOW voltage drop

Jim Painter
 

Skip, check with the power company. If the noise is coming from their equipment, they are probably responsible for fixing it.

Jim….KQ3S

On Jun 14, 2021, at 12:00 PM, Skip Davis via groups.io <skipnc9o@...> wrote:

David this is so true, I took my KX3 and portable HF whip antenna to my new under construction home and was elated to find the noise level only about S1 or 2. I was standing in the room that was to be my future ham shack. After moving in and setting up my station the noise level was S7, so with KX3 and portable antenna in hand I started investigating the sources of noise around the house. To my surprise the biggest culprit is the wide band noise from the power meter and all conduit into the meter and to the power panel up here is plastic.
I was able to reduce some of the noise by upping the size of the grounding cable but could never get ride of it totally. I run most of my station off a battery system and turn on the charger when not operating, so when I’ve had power outages it goes quite again. Even running my generator the noise is half of what is seen from the power company.
Sorry for the off topic to everyone else but this might help others to find that elusive noise they are trying to track down because pulling the main breaker doesn’t eliminate the meter from the equation.

Skip Davis, NC9O





Re: #QCX+ D3 MOD - D3 replacement for LOW voltage drop

Ian MM0GYX
 

Cris,

I don't intend to build it, I can manage the loss of 1 watt, difference between 4 and 5 watts is 1 dB, but good work anyway for those who need the extra power.

By the way, I see the Vgs of this MOSFET is +/- 20 volts, I think you could replace the diode with a resistor of similar size to the one you have in circuit already. I realise it's always better to use the Zener to protect the MOSFET if it has low Vgs.

73,

Ian MM0GYX


Re: #QCX+ D3 MOD - D3 replacement for LOW voltage drop

Skip Davis
 

David this is so true, I took my KX3 and portable HF whip antenna to my new under construction home and was elated to find the noise level only about S1 or 2. I was standing in the room that was to be my future ham shack. After moving in and setting up my station the noise level was S7, so with KX3 and portable antenna in hand I started investigating the sources of noise around the house. To my surprise the biggest culprit is the wide band noise from the power meter and all conduit into the meter and to the power panel up here is plastic.
I was able to reduce some of the noise by upping the size of the grounding cable but could never get ride of it totally. I run most of my station off a battery system and turn on the charger when not operating, so when I’ve had power outages it goes quite again. Even running my generator the noise is half of what is seen from the power company.
Sorry for the off topic to everyone else but this might help others to find that elusive noise they are trying to track down because pulling the main breaker doesn’t eliminate the meter from the equation.

Skip Davis, NC9O


Re: tuning without detents

Johan Bodin
 

That was fun to read. I did something similar with a PIC MCU many years ago. I put a lever on a pot with spring return to center position. Much like a 1-axis joystick. I remember that the software had a small deadband in the middle to prevent frequency from slowly creeping away if there were a few ADC lsBits of offset, either electrical or mechanical.

I used it on two QRP rigs, one with varicap tuned VFO and a huff'n'puff stabiliser and another rig with AD9835 DDS VFO.

73
Johan SM6LKM

Den 2021-06-14 kl. 09:39, skrev Ronan Cantwell:

The chat earlier about maximum encoder pulse speeds reminded me of this little add-on I made for my original QCX "classic" radios (see video linked below). It uses an attiny85 to emulate the encoder pulses. A pot is used to control the speed and direction of the virtual encoder. With the pot in its middle position, the encoder is at rest. Turning to the left or right will tune down or up at a variable rate starting very slow and ending pretty fast indeed at the end of the pot's range.

While the tuning method seems a little odd at first, it actually becomes very intuitive and is great for scanning through the bands for activity.