Date   

Re: use QCX before alignment #40m

Ham Radio
 

I would not use the QCX without a dummy load.  Too easy to make a error.

Do you not have a two  100 ohm resistors or four 220 ohm resistors in your junk box that you could use as a dummy load?  

Check the final resistance before transmitting to make use the dummy load is around 50 ohms.


--
73, Bernie, VE3FWF


Re: use QCX before alignment #40m

George Korper
 

Good question. I wouldn't, because I have become very cautious.
If you are very cautious, just be certain you stay in practice mode.
I would also find some resistance and make up my own little dummy load.
It is just because there are no protections for the finals and before you are
totally familiar with a new rig mistakes happen. 


On Sun, Jun 14, 2020 at 8:04 AM <expat48@...> wrote:
Hi all,
I have the QCX 40m built but awaiting dummy load to align it...
Can one use the practice CW mode before alignment and without a dummy load???


use QCX before alignment #40m

expat48@...
 

Hi all,
I have the QCX 40m built but awaiting dummy load to align it...
Can one use the practice CW mode before alignment and without a dummy load???


Re: QCX firmware upgrade from 1.00g to 1.05.

Richard G4TGJ
 

You also need the EEPROM file from Hans.
--
73
Richard
G4TGJ


Re: QCX firmware upgrade from 1.00g to 1.05.

Alan G4ZFQ
 

Can someone please point me in the right direction regarding the correct fuse setup?
John,

The fuses are wrong. https://sites.google.com/site/g4zfqradio/qrplabs_program_chip_with_USBasp

BUT as Bob says you cannot flash a new chip without Hans' help.

73 Alan G4ZFQ


Re: QCX firmware upgrade from 1.00g to 1.05.

Richard G4TGJ
 

There's nothing special about the ATMega used in the QCX, you just need to program the correct fuse bits. Hans will supply the file for this.
--
73
Richard
G4TGJ


Re: Shipping FAQ

Dave 'TXJ
 

Most recent surface mail order arrived yesterday, the order placed before that is still "somewhere". However an order selected to come via TNT was here in 24 hours, amazing!

73 Dave


Re: QCX firmware upgrade from 1.00g to 1.05.

N3MNT
 

The problem is you are trying to program generic parts.  The parts from QRP-Labs are protected to protect the firmware from clones. 


QCX firmware upgrade from 1.00g to 1.05.

João Cunha Lopes
 

Hi all.

I have been trying to upgrade my QCX firmware from 1.00g to 1.05.
Due to the world wide pandemic there are huge delays in mail, so I opted to buy a couple of ATMEGA328 locally.
Chips are branded ATMEL and they are "ATMEGAS328P U". Chip ID, when read by my programming software, is (hex) 1E950F.
I have read that this may be a problem when using avrdude:

avrdude.exe: Device signature = 0x1e950f
avrdude.exe: Expected signature for ATmega644P is 1E 96 0A
Double check chip, or use -F to override this check.

I'm using an old generic programmer (GQ-4X) with ISP interface to the chip. For my programmer the 1E950F is not a problem and it can work fine with this chip.
I've loaded firmware 1.05 into the "ATMEGAS328P U" and all when well.
When I tried the chip on the QCX all I got was a line with "##########################". The radio does not boot.
I checked the programming again and the firmware is in the chip.

There are a couple more things that I would like to try before giving up on this.
Fuses?

My programmer allows me to set the following:



Also, I have read that:

"There are a total of 19 fuse bits that are used in the ATmega328P, and they are separated into three different fuse bytes. Three of the fuse bits are contained in the "Extended Fuse Byte", eight are contained in the "Fuse High Byte," and eight more are contained in the "Fuse Low Byte".

From the above image its seems that I can set each and every fuse.
Can someone please point me in the right direction regarding the correct fuse setup?

Also I have noticed the OSC calibration bytes, 4MHz, 8MHz. How important is ths?

Anyway, If someone could point me to all the correct fuse values I would appreciate it.
Thank you.

John, CT2HME


Re: WSPR data analysis #qcx40 #wspr

Ted 2E0THH
 

Hi Graham, Michael and Alan

I was just about to set about this task with MS Access and thought I would quickly try the Windows Command line approach before I started.

It's brilliant! Saved me a morning's work, thank you! The results loaded up into MS Excel without problem.

My example:
C:\Users\micro\Desktop>FINDSTR 2E0THH wsprspots-2020-05.csv > 202005_WSPR_DB_results.csv

For others, note that I performed the processing on my desktop. DOS processed files can get easily lost unless you define the directory before you start.

So first I copied the large WSPR download onto my desktop
Then in the command window, I changed the directory using the cd command (change directory) so that all actions would take place on my desktop, thus
C:\>cd C:\users\micro\desktop (you will need to modify this line to match your own desktop location. An easy way to find this is to right click any existing file on your desktop, click properties and a window opens. There you will see your desktop location)

So now, when the command executes, it places results csv on the desktop too.

Thanks and I hope this extra info helps.

73s Ted
2E0THH


Re: Shipping FAQ

KI7MWA
 

...and...now...Brazil!  Talk about International shipping!


Re: WSPR data analysis #qcx40 #wspr

Trevor VK3PD
 

Dont know if this helps but  libreoffice has lots of  advantages over openoffice and it runs on linux


Re: Question about QRPLabs band-pass filter #bpf #lpf

ajparent1/KB1GMX
 

I need to disable spell wreck as there are several copies running
but not on my system.

Allison
-------------------------------
Please reply on list so we can share.
No private email, it goes to a bit bucket due address harvesting


Re: Question about QRPLabs band-pass filter #bpf #lpf

makkiato@...
 

thanks! 


Re: Question about QRPLabs band-pass filter #bpf #lpf

 

"Badpass"... is that like "Leeloo Dallas, MultiPass" ?

For those weirdo's like me who like cult movies.

I'll shut up now.

Julian N4JO.

On 6/13/2020 1:32 PM, ajparent1/KB1GMX wrote:
Dave is right the voltage limits of the caps preclude using them for more than
maybe 1.00W.  It would be suggested to say under 200mW.

If you need badpass for highe rpower there are designes out there,,,
See sepetember 1988 QST for an example.

Allison
-------------------------------
Please reply on list so we can share.
No private email, it goes to a bit bucket due address harvesting


Re: Question about QRPLabs band-pass filter #bpf #lpf

ajparent1/KB1GMX
 

Dave is right the voltage limits of the caps preclude using them for more than
maybe 1.00W.  It would be suggested to say under 200mW.

If you need badpass for highe rpower there are designes out there,,,
See sepetember 1988 QST for an example.

Allison
-------------------------------
Please reply on list so we can share.
No private email, it goes to a bit bucket due address harvesting


Re: Simple firmware instructions for USBASP #qcx #firmware

Guy
 

Thanks Ted.


Re: Gps problem.

David Lockard
 

Yep they are.


From: QRPLabs@groups.io <QRPLabs@groups.io> on behalf of N3MNT <bob@...>
Sent: Saturday, June 13, 2020 11:27:41 AM
To: QRPLabs@groups.io <QRPLabs@groups.io>
Subject: Re: [QRPLabs] Gps problem.
 
If the tx and rx lines are connected are the connected correctly.


Re: Gps problem.

N3MNT
 

If the tx and rx lines are connected are the connected correctly.


Re: Question about QRPLabs band-pass filter #bpf #lpf

Dave
 

The band pass filters use a primary winding to get signal into and out of the toroids.  There are many more secondary turns than primary, and this increases the impedance from 50 ohms to something much higher.

The coupling capacitors between resonant circuits are probably rated at 50 volts, and never see that when dealing with received signals.  But pumping in transmit power and then raising the signal impedance raises the signal voltage which will likely exceed the coupling capacitor rating to the point of damage.

There are several choices of transmit band pass filters available, and they tend to keep the signal impedance low to avoid the high voltages which come with high impedance circuits.  The W3NQN transmit band pass filter design does increase the internal impedance and needs high voltage capacitors, like 3kV!

Dave


On Jun 13, 2020, at 07:43, makkiato via groups.io <makkiato@...> wrote:



Hello,

I have a question regarding the BPF kits:

https://qrp-labs.com/bpfkit.html

I know they are supposed to be used as "receiver" bpf's, but I am curious if I could use them to filter the output of a low power amplifier (around 2/3W).

So my question is:

 

Question: does anyone know what is the max power rating of these BPF ?

I could fine on the website that the LPF kits (https://qrp-labs.com/lpfkit.html) can safely handle 10W.

 

Thanks!