So, I did the mod on my 40m QCX a couple weeks ago.. replacing the original 10 uf electrolytic caps with the recommended 1 uf ceramic caps at C21 and C22 (IIRC).

Anyhow, though it is not what it was before, there still remains a bit of a thump on the keying. Is this the way it is...do others experience this?

I think I would find it fatiguing over time... in fact I did have a (rare) 45 minute rag-chew QSO last week - but not on the QCX.

Which is to say that if this was lessened to the tolerable level/removed then I would love to pair it up with the new 50 watt amp.

Anyhow, comments are welcome. I will admit I hear the same sort of thing on the Dave Benson DDS rigs from around 2002 or so. 

72

Brian VE3VAW

>the manual also also includes a
> substantial section detailing the circuit theory.

Hans,

I'm sorry to say I probably will not buy one.
BUT section 6 of the manual is worth the cost of the kit!
Absolutely amazing how much you have detailed and the T-R switching that
beats commercial rigs needs patenting!

73 Alan G4ZFQ

Hello all QRP Labbers... (don't forget to VOTE QRP LABS!)

Here is a new kit, this is a 50W PA kit for the QCX. See http://qrp-labs.com/50wpa . Price is $29.50 (approx £22 or 26€) which includes the PCB, all components and connectors, and two large black anodized aluminium heatsinks. The amplifier produces up to 50W power with full break-in (QSK), with 20V 5A supply. At 13.8V supply on 40m CW the measured power output is 25W. 

A beautiful enclosure for it is also available, price $16 (approx £12 or 14€), see http://qrp-labs.com/50wpabox . It is made from black anodized extruded aluminium with front and rear panels drilled and printed to match the 50W PA. 

A key feature of the kit is fast solid-state transmit/receive switching (relays!) - which allows full break-in (QSK) operation using the QCX. 

The kit can be built for 40, 30 or 20m bands, which covers 90% of QCX kits. It can also be built for other bands if you supply your own Low Pass Filter components. Multi-band would be possible if you connect your own switched external Low Pass Filters. 

Please refer to the FAQ on the 50W PA page http://qrp-labs.com/50wpa if you have any questions. The 68-page manual is very detailed making construction un-daunting, and the manual also also includes a substantial section detailing the circuit theory. 

Despite our dedication to QRP (5W and under), there are occasions when a bit more power is needed, and this kit provides it. For example, you want to QSO a particular station on a sked at a particular date and time; or when conditions are poor, or you want to work particular DX... any number of reasons. 

During the summer of 2019 the 40m version of this amplifier was tested extensively here in QTH KM46, with well over 500 QSOs in the log. Despite the poor band conditions and my very mediocre antenna and location, QSOs ranged from New Zealand and Japan in the East, to US in the West; Finland in the North, down to Saudi Arabia and everywhere in between. (500+ real QSOs averaging 10 minutes, not contest exchanges). During QSOs I estimate around 90% of correspondents are using power in the 50-100W range, the remaining 10% operate with higher power than that or a few of them, with QRP (5W and below). This 50W PA kit puts you and your QCX on a level playing field with the majority of CW operators on the bands.

So pimp your station, pump up the watts... have some fun with a new project... the 50W PA kit http://qrp-labs.com/50wpa 

73 Hans G0UPL

http://qrp-labs.com

one last thing... soldering iron.

The average one I see in use by people is a reasonable quality temperature controlled
unit turned too far up with a cruddy tip with rough edges.  Replace the tip turn it down
and try to not use the tip as a chisel.   

Hint put it back in the holder without cleaning it after making a joint.  Clean it on the
way out and make sure its shiny clean before touching the joint.  If it gets dark and
grungy too fast its likely way to hot.


Or an el cheapo that run at 900 degrees or hotter, with a cruddy black tip.
Get a soldering iron!

Both users tend to have terrible soldering and complain they can't get the solder to melt
and they burn up boards in the process.  The tip has to be clean to transfer heat.  If you
beat it up or use poor solder and high heat (trying to get it to work) that tends to destroy
tips amazingly fast.  I've see a few kill a tip in hours.
 
I tend to use tips for literally thousands of hours (years) of build time.  Quality solder,
good care, and moderate temps.  

I bought the current Weller WES51 some 20 years ago and the current tip is more than
3 years old.  The only thing was to repair the cord to the handle.  My other iron is a
really old TCP60 (curie point temp control) from about 1979ish, the .25" wide tip on
that is maybe 10 or more years old.  I use that for SMT parts as its wide!

-------
Please reply on list so we can share.
Off list email goes to trash, I had to due to scrapers.

Hello all QRP Labbers... (don't forget to VOTE QRP LABS!)

Here is a new kit, this is a 50W PA kit for the QCX. See http://qrp-labs.com/50wpa . Price is $29.50 (approx £22 or 26€) which includes the PCB, all components and connectors, and two large black anodized aluminium heatsinks. The amplifier produces up to 50W power with full break-in (QSK), with 20V 5A supply. At 13.8V supply on 40m CW the measured power output is 25W. 

A beautiful enclosure for it is also available, price $16 (approx £12 or 14€), see http://qrp-labs.com/50wpabox . It is made from black anodized extruded aluminium with front and rear panels drilled and printed to match the 50W PA. 

A key feature of the kit is fast solid-state transmit/receive switching (relays!) - which allows full break-in (QSK) operation using the QCX. 

The kit can be built for 40, 30 or 20m bands, which covers 90% of QCX kits. It can also be built for other bands if you supply your own Low Pass Filter components. Multi-band would be possible if you connect your own switched external Low Pass Filters. 

Please refer to the FAQ on the 50W PA page http://qrp-labs.com/50wpa if you have any questions. The 68-page manual is very detailed making construction un-daunting, and the manual also also includes a substantial section detailing the circuit theory. 

Despite our dedication to QRP (5W and under), there are occasions when a bit more power is needed, and this kit provides it. For example, you want to QSO a particular station on a sked at a particular date and time; or when conditions are poor, or you want to work particular DX... any number of reasons. 

During the summer of 2019 the 40m version of this amplifier was tested extensively here in QTH KM46, with well over 500 QSOs in the log. Despite the poor band conditions and my very mediocre antenna and location, QSOs ranged from New Zealand and Japan in the East, to US in the West; Finland in the North, down to Saudi Arabia and everywhere in between. (500+ real QSOs averaging 10 minutes, not contest exchanges). During QSOs I estimate around 90% of correspondents are using power in the 50-100W range, the remaining 10% operate with higher power than that or a few of them, with QRP (5W and below). This 50W PA kit puts you and your QCX on a level playing field with the majority of CW operators on the bands.

So pimp your station, pump up the watts... have some fun with a new project... the 50W PA kit http://qrp-labs.com/50wpa 

73 Hans G0UPL

http://qrp-labs.com

> Game over as I don't have a replacement for IC3.

George,

OK, although they should be easy to source. But I am thinking that
further faults may be found if the voltages are checked.
Maybe look at again sometime, you learn more about how something works
when it does not work!

73 Alan G4ZFQ

Hi,

I just got a disturbing mail from Yahoo.

If I understand correctly all content of our group will be deleted and the group will become something not open to public.
Exchanges only be e-mail and new menbers only by invitation.

To me that looks like the end of our communication and as if all the usefull information stored in the history of this group to disappear.

Any remedy or chance to move the group somewhere else ?

73's
Martin