Date   

Re: Enclosure for QCX +

John Baines
 

Hi,

If you go to the QCX+ Shop page and select ‘Enclosures’ from the header, you will find the enclosure on the bottom row. Not bad for $25.

73/72
John
M0JBA

On 27 Sep 2021, at 14:01, DK <donaldphilbin@...> wrote:

I did not purchase an enclosure when I purchased my QCX+ because I wanted to be sure that I could build it successfully first. Well I did and now I see that the case is no longer available on the QRP Labs site nor from BaMaTech :(. What are my options?

Thank you in advance,

DK KD6TK 


Enclosure for QCX +

DK
 

I did not purchase an enclosure when I purchased my QCX+ because I wanted to be sure that I could build it successfully first. Well I did and now I see that the case is no longer available on the QRP Labs site nor from BaMaTech :(. What are my options?

Thank you in advance,

DK KD6TK 


How low can the receiver kit go?

David Giles
 

Hello All,

Can the receiver kit be used on 2200m or 630m (assuming I use an appropriate band pass filter)?

Will the trifilar toroid T3 be suitable as is or do I need a bigger toroid or more turns?

David VK5DG


Re: 10W HF Linear PA - Gain Flatness

swallowp@...
 

Hi both,

Thanks for the feedback.  I wondered if anyone had already looked at this as there are several mentions of using the amp as a gain block on this site.  It's a bit of a fiddle to get at the underside of the board to experiment without making different heat sinking arrangements.  Inherent flattening may not be worth the effort, but it would be nice to meet the +/-1dB example published in the assembly manual. 
I have not explored changing the supply voltage yet, though I notice that the HF gain increases slightly with voltage.

I noted the input impedance variation from the notes on the web site and my own measurements.  The input and output were well padded (50 Ohms) for my gain measurements.

I'm aiming for 2-3W clean output into 50 Ohms 2-50MHz with an adjustable levelling loop for constant voltage at the output connector.  The source will be a signal generator with an inherently fairly flat output. The relatively bomb-proof design and linearity of this amp make it an ideal building block.  I could just buy an instrument amplifier, but where is the fun in that?

73,

PeterS          G8EZE


Re: 50 Watt Amp

Leland L. Bahr
 

Better yet, buy the QRP Labs modules and use your own caps.  In quantities of ten, 250 volt COG caps are around 30 cents each.

Lee, w0vt

On 9/26/2021 9:44 PM, Leland L. Bahr wrote:

Good question.  Probably not.  I know Hans uses 250 volt NP0 caps in the amp and probably 100 volt caps in the modules which he says are marginal due to spikes in the amp.  I guess you could then buy the relay board and make up your own modules using  250 volt NP0 caps.  The T50 cores should be OK for 50 watts and more.  Cores should be no problem.  Not sure about the relays.  Most likely OK if you don't HOT SWITCH the relays.

Lee, w0vt

On 9/26/2021 9:28 PM, Julian N4JO wrote:
Are they rated for 50W output?
--
Julian, N4JO.


Re: 50 Watt Amp

Leland L. Bahr
 

Good question.  Probably not.  I know Hans uses 250 volt NP0 caps in the amp and probably 100 volt caps in the modules which he says are marginal due to spikes in the amp.  I guess you could then buy the relay board and make up your own modules using  250 volt NP0 caps.  The T50 cores should be OK for 50 watts and more.  Cores should be no problem.  Not sure about the relays.  Most likely OK if you don't HOT SWITCH the relays.

Lee, w0vt

On 9/26/2021 9:28 PM, Julian N4JO wrote:
Are they rated for 50W output?
--
Julian, N4JO.


Re: 50 Watt Amp

 

Are they rated for 50W output?
--
Julian, N4JO.


Re: 50 Watt Amp

Leland L. Bahr
 

Ron, Curt, and others,

Why not piggy back a QRP Labs "Ultimate Relay Switched LPF" costing $16 and then plug in 5 or 6 QRP Labs LPF kits" costing $4.60 each?  With 5 LPF kits the total cost would be $39.00. (80,40,30,20,17 meters)  You could use an outboard rotary switch to engage any relays controlling the band you want activated. Switch would cost $2.00 or so.  The board could be mounted above the amp board and all you would do is connect the input and output of the LPF board to the amp board.  You could install a voltage regulator to reduce the amps 20 volt supply down to 5 volts to be used to drive the relays.  Of course you would have to then come up with your own cabinet for all this as the QRP Labs Amp cabinet would be too small.  I think this is about what Ron did using his own filter board and parts.  This sure would be cheaper then buying five amplifier kits with cabinets!

Lee, w0vt

On 9/26/2021 6:07 PM, Leland L. Bahr wrote:
Has anyone on here made their 50 watt amp a multi band amp? (Manually switched LPF)

Lee, w0vt





Re: 50 Watt Amp

Curt wb8yyy
 

Lee

The funny thing an extra amp kit may cost less than the relays. Don't let this stop you from getting one. I use one with an 80m qcx plus. Power is a bit lower due to the switching diodes not working as well, but it's enough gain to help with qsos. I did modify a sw40 to provide the tr switching but haven't used it yet. If you have some opposite gender bnc connectors, Ron's suggestion works well I do this with my ubitx on 160m. 

Curt


Re: 50 Watt Amp

Ronald Taylor
 

Hi Lee. I actually did do that with two different amps using two different approaches. The first one involved an amp built for 20 meters and two outboard lowpass filters… 30 and 40 meters. Leave the 20 meter filter in the amp and just add the necessary outboard filter for the lower band of interest. 

On the other one, I built an amplifier with no filter components on the board and built 5 filters on a separate board with relay switching for 80,40,30,20&17 meters. 

Overall I think the first method probably worked out the best, complexity wise. The amplifier performance, in my particular case with the 5-band switched filters, fell off at 80 and 17 meters. Whereas it performed pretty much as expected on 40, 30 and 20 meters and the external add-on filters of the first option were not a big deal to add and remove. 

Hope that helps. 

73… Ron

On Sun, Sep 26, 2021 at 16:07 Leland L. Bahr <w5drc@...> wrote:
Has anyone on here made their 50 watt amp a multi band amp? (Manually
switched LPF)

Lee, w0vt







50 Watt Amp

Leland L. Bahr
 

Has anyone on here made their 50 watt amp a multi band amp? (Manually switched LPF)

Lee, w0vt


Re: QCX -Mini Society Member #20m

wa8yan.radio
 

Thanks Mike for your kick in my brain for moving components off the board to overcome the height problems.  I probably would still be stuck in the make the box fit the board mode instead of make the board fit the box as per your idea.  So thanks for that reply.  This little project is a great QCX accessory.
73 Phil WA8YAN



Sent from my Verizon, Samsung Galaxy smartphone


-------- Original message --------
From: Mike Besemer - WM4B <mwbesemer@...>
Date: 9/26/21 12:56 PM (GMT-05:00)
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] QCX -Mini Society Member #20m

Nicely done, Phil.  I have mine built now, but need to find an enclosure.

 

73,

 

Mike

WM4B

 

From: QRPLabs@groups.io [mailto:QRPLabs@groups.io] On Behalf Of wa8yan.radio via groups.io
Sent: Sunday, September 26, 2021 12:19 PM
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] QCX -Mini Society Member #20m

 

Hi everyone.  I found a plastic box at Joann Fabrics when my wife sent me to buy some yarn.  As a variant from Mike's idea, I moved the BNC connectors off the board and mounted the PCB on some stand offs and a few washers as shims to get the height right, cut the appropriate holes in the cover and voila, a SWR/PWR meter in a case.  The box was a little longer than I needed so I put a small parts baggie in the excess space and am loading it up with pl to bnc adapters and bnc dummy load, maybe even a very shot jumper cable.

73 Phil WA8YAN

 

 

 

Sent from my Verizon, Samsung Galaxy smartphone

 

 

-------- Original message --------

From: "wb8yyy via groups.io" <wb8yyy@...>

Date: 9/18/21 1:11 PM (GMT-05:00)

To: QRPLabs@groups.io

Subject: Re: [QRPLabs] QCX -Mini Society Member #20m

 

Phil

If you haven't built yet, then Mike's plan. 

If you have already built it, maybe a kitchen container. You can open the lid the few times you might use this. Looks like you are equipping things well. Hope you have your antenna figured out, some form of efhw may be least visible. 

Curt


Re: QCX -Mini Society Member #20m

Mike Besemer - WM4B
 

Nicely done, Phil.  I have mine built now, but need to find an enclosure.

 

73,

 

Mike

WM4B

 

From: QRPLabs@groups.io [mailto:QRPLabs@groups.io] On Behalf Of wa8yan.radio via groups.io
Sent: Sunday, September 26, 2021 12:19 PM
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] QCX -Mini Society Member #20m

 

Hi everyone.  I found a plastic box at Joann Fabrics when my wife sent me to buy some yarn.  As a variant from Mike's idea, I moved the BNC connectors off the board and mounted the PCB on some stand offs and a few washers as shims to get the height right, cut the appropriate holes in the cover and voila, a SWR/PWR meter in a case.  The box was a little longer than I needed so I put a small parts baggie in the excess space and am loading it up with pl to bnc adapters and bnc dummy load, maybe even a very shot jumper cable.

73 Phil WA8YAN

 

 

 

Sent from my Verizon, Samsung Galaxy smartphone

 

 

-------- Original message --------

From: "wb8yyy via groups.io" <wb8yyy@...>

Date: 9/18/21 1:11 PM (GMT-05:00)

To: QRPLabs@groups.io

Subject: Re: [QRPLabs] QCX -Mini Society Member #20m

 

Phil

If you haven't built yet, then Mike's plan. 

If you have already built it, maybe a kitchen container. You can open the lid the few times you might use this. Looks like you are equipping things well. Hope you have your antenna figured out, some form of efhw may be least visible. 

Curt


Re: UProc Reset / Micro"Processors" vs Micro"Controllers"

 

Exactly right.
Some consumer devices with embedded microcontrollers have a special purpose "reset" button which, if held for some number of seconds, initiates some form of "return to factory configuration", but that is vastly more than simply resetting the microprocessor/microcontroller which "merely" restarts code execution at the reset vector, which is the same vector that is used at power-on.

As Mont correctly says, microcontrollers have built-in peripherals which have their own control and configuration registers, and those built-in devices are returned to a default state by activation of the processor reset input too (again, different from the multi-function pin on many devices). Peripheral devices in a microprocessor based device such as a personal computer may or may not share access to the processor reset line, so it may be up to the processor to properly configure those devices and bring them to a known operating state.

As Rob says, the "return to factory configuration" - or "ground zero reset" as one might call it in Hans' QCX products is a very non-accidentally triggerable menu item.
--
Julian, N4JO.


Re: QCX -Mini Society Member #20m

wa8yan.radio
 

Hi everyone.  I found a plastic box at Joann Fabrics when my wife sent me to buy some yarn.  As a variant from Mike's idea, I moved the BNC connectors off the board and mounted the PCB on some stand offs and a few washers as shims to get the height right, cut the appropriate holes in the cover and voila, a SWR/PWR meter in a case.  The box was a little longer than I needed so I put a small parts baggie in the excess space and am loading it up with pl to bnc adapters and bnc dummy load, maybe even a very shot jumper cable.
73 Phil WA8YAN



Sent from my Verizon, Samsung Galaxy smartphone


-------- Original message --------
From: "wb8yyy via groups.io" <wb8yyy@...>
Date: 9/18/21 1:11 PM (GMT-05:00)
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] QCX -Mini Society Member #20m

Phil

If you haven't built yet, then Mike's plan. 

If you have already built it, maybe a kitchen container. You can open the lid the few times you might use this. Looks like you are equipping things well. Hope you have your antenna figured out, some form of efhw may be least visible. 

Curt


Re: UProc Reset / Micro"Processors" vs Micro"Controllers"

Rob Giuliano
 

Good commentary.
I will add something that fits along the original thread:
   "... Since I will want to do a UProc reset to get back to the diagnostic mode, ..."
In a sense, the expectation was that shoringt the RESET pin to ground to get back to the "factory settings" and get back to "Diagnostic Mode".

Neither the RESET pin on a microcontroller, nor the reboot sequence of a microprocessor (as in PC) should take your system back to a "factory reset".

For a computer, this would mean uninstalling all of the users applications on the hard drive that were not installed at the factory.
   Can you image if Microsoft or motherboard manufacturers ever decided to reset to factory settings with a <Ctrl><Alt><Del>?
For the microcontroller, this would be clearing EEPROM and setting the bit for (what I will call) initial startup.

Hans' has a menu item to do that, in the same way your PC has ways of factory resetting to a known state - typcially on a separate hard drive partition.
Once you have started to configure the device, you probably don't really want to go back to "factory settings", except under certain conditions.




--
Rob KB8RCO


Re: Finally on the air #wspr #u3s #loveit

Albert Tatlock's Greatest Hits - Vol 1
 

On Sat, Sep 25, 2021 at 12:43 PM, Bertel Andresen wrote:
I'm living in Gothenburg, Sweden.
I used a be a regular at the Dancing DIngo down at Lorensbergsgatan some years ago,
and would also sit down by the River Gote with my old Sony SW100 once I had finished
work for the day.


How on earth is this possible?
From what I *thought* I knew about distance vs power, it is not, but I'm still doing it...
I have my newly built U3S finally on the air, temporarily hooked up on my kitchen table, not even boxed yet.

Welcome to the alternative side of amateur radio ;-)

The U3S is still unique after all these years.
I can't imagine life without either U3S and the collection of predecessors now.



Re: Finally on the air #wspr #u3s #loveit

M0PWX
 

@bertel

 

Welcome to true QRP with the U3s, Hans designed a truly magical box that is fun to build and performs so well

 

Give us a bit of info on your QRZ page about you and your station

 

Have a look at QRSS as well, that another fun QRP mode

 

You can run more than one mode in sequence on the U3s

 

I run WSPR, then FSKCW for QRSS, then slow hell to print my Callsign, like G0MBA and G0PKT below

 

 

QRSS Plus (swharden.com)

 

The New Age of QRSS (swharden.com)

 

Peter

M0PWX

 

M0PWX Grabber Page (qsl.net)

 

 

How on earth is this possible?
From what I *thought* I knew about distance vs power, it is not, but I'm still doing it...
I have my newly built U3S finally on the air, temporarily hooked up on my kitchen table, not even boxed yet.
A couple of lab cables to the PS and such.
A fairly simple HFJ-350M antenna on the balcony, grounded in the railing, tuned with a simple analyzer.

At for example 20m, with about 180mW out to the antenna.
I'm getting spots from all over Europe, Moscow, Crete, Iceland, The Canary Islands AND North Eastern US.
I'm living in Gothenburg, Sweden.
6147km (WZ7I) on 180mW, 29uW/km, OK.....

I find this truly amazing.
What can one do with such simple equipment?


Re: Finally on the air #wspr #u3s #loveit

John Kirby
 

 SM6OES, Bertel,

YES QRPp = tons of fun!

Just a suggrestion...
...double the fun...

Go to
>>>https://www.qrz.com/<<<
and set up your free account

...You have 33 lookups already

72 73
John
N3AAZ
FM19


Re: 5W PA on 472Khz?

Mont Pierce KM6WT
 

On Sat, Sep 25, 2021 at 10:38 AM, fintronicsusa wrote:
Am I assuming correctly that the 5w PA will not operate there as-is?
While the webpages for the 5W HF Amp don't mention it's specific frequency range, The Assembly Manual does...

Check the Assembly Manual, page 40 (click here).

5.5.8 Optimising for a particular band, or even Class-E operation
The recommended 10 trifilar turns on transformer T1 are suitable for the whole of HF but perhaps not
optimum at the extremes. It would be worth experimenting with fewer turns at the upper frequency
turns and perhaps more turns at MF/LF e.g. the 600m band.

For higher power operation the FT50-43 itself may saturate and so two (or more) could be stacked
together to reduce the load on each one.

Finally Class-E operation can offer extremely high efficiencies, over 90%, for continuous carrier
applications such as this. It’s an extensive topic, way outside the scope of this assembly manual.
Class-E will only be possible on a single band, unless you employ switching of the components.


6. Power Amplifier characteristics

These measurements were made using a QRP Labs Ultimate3S transmitter kit as driver, with a single
BS170 transistor running at 5V supply. The curves show the Power Amplifier kit with 12V and 13.8V
supply voltage. The output of the PA kit was connected to a QRP Labs Low Pass Filter Kit, whose
output was connected to a QRP Labs 50-ohm 20W Dummy Load kit. Measurements were made on
600m, 160m, 80m, 40m, 30m, 20m, 15m and 10m bands (frequencies 0.5, 2, 3.5, 7, 10, 14, 21 and
28MHz respectively).


km6wt