Date   
Re: Low Power Output - S/N 2857 - 20M

Alan de G1FXB
 

Hi All,

Like I said, posted in the interest of a alternative view.
People who search the threads and may not go beyond this one to read the others.....
So to provide comment from the kit supplier, on this subject but on another thread
Not intended as a definitive statement / cure all, for everyone.

We debated the unknowns,
No# of wire turns and torrid material reproducibility, compared the colour paint, to death previously......

As ever components have a 'tolerance' value, both in electrical value and quality.
capacitors, torroid material variations, and the greatest variable is our winding / turn spacing / mutual coupling?

(It's the RX BPF but
Didn't one builder check the inductance of the three identical windings on T1 and two were close and the third was wildly out.
I'm not sure that was ever solved?)

It all adds & subtracts up, we hope it all works in our favour. Sometimes it doesn't.
When it doesn't then it requires a change to the properties of the circuit.

Alan

On 21/02/2018 10:16, Richard Harris via Groups.Io wrote:
Hi Alan,

Many thanks for the link - I think Hans posted this after I posted about the warming up of C25/C26.  I'm going to disagree with Hans that if the LPF frequency is too low then it much result in increased dissipation in the filter components.  This would only occur if the currents within the filter increase significantly with, say, greater than optimum inductor values (i.e. lower cut-off frequency) and the capacitors have a significant loss component.

Richard G3OTK



On Tue, Feb 20, 2018 at 05:26 pm, Alan de G1FXB wrote:

Hi Richard,
In the interest of providing an alternative view,

 ?if you observe capacitor heating in the LPF ?

https://groups.io/g/QRPLabs/message/21483


If the capacitors get hot, It maybe because the LPF cut-off is too low?

http://qrp-labs.com/qcx/qcxtrouble.html#lowpower


Alan


On 20/02/2018 20:18, Richard Harris via Groups.Io wrote:
Hi Jim,

A builder of a 20m QCX mentioned that C25 and C26 (390pF) in the 
output filter were getting hot when transmitting.? I had just 
completed a 20m QCX and so *I checked these capacitors with an IR 
thermometer and they were also warming up on transmit.*? I cut them 
out and replaced with 330pF + 56pF NPO 100v ceramic capacitors 
(soldered on the back of the PCB) and the output power rose 
significantly? It may be worth checking these capacitors, particularly 
if you have the 20m version.

Richard G3OTK


On Tuesday, 20 February 2018, 19:49, Jim - AC0OW <ars.ac0ow@...> 
wrote:


As-built had power out of 1.44 watts (24vpp) at L1 out (with 50 ohm 
dummy load). ?Checked resistance via L1,L2,L3 - All okay. ?Power at 
BS170 drains was ~ 5 watts. ?Following fault-finding guidance, I took 
2 turns off each of L1,L2,L3 and again checked continuity. ?Power went 
up to 2.25 watts (30 Vpp). ?Not much improvement. ?Checked power just 
prior to L1 and got 5 watts. ?So, Where should I go from here. ?Looks 
like something after L1 must be loading down the Xmit chain. ?Any 
suggestions would be appreciated.

Otherwise rig is great. ?Worked PJ4 for first contact. even with QRPp Hi.







Re: Loud tone on QCX 40 #qcx

KE0IMD
 

I have not, no.

Re: Unresponsive volume control

GD
 

Braden, looking down on the QCX with the control in the bottom left corner the right hand control pin should be at ground. It should measure zero ohms from this pin to ground.You say that you can vary the resistance of the control. The middle pin is connected to a wiper that sweeps around a carbon track inside the pot, this carbon track is connected to the Left and Right pins with the Wiper deciding  the selection of resistance needed  for audio control. This applies also to the Right pin, Checking this varying resistance with the pot in situ gives a false confidence. You could remove the pot, measure across Right and Left Pins, confirm there is continuity, measure the Wiper centre pin to Left and Right pins. If the internal carbon track is not connected under a crimp you could remove the pot casing and have a look. Bear in mind you installed this pot by tightening it to the PCB with its nut and washer so did you make sure the pins were aligned to PCB holes before fixing and not put the 3 pins under strain?

73 Geoff G4CAO

Re: ProgRock - Serial

Robin Midgett
 

Right, and I'm thankful. I have an Arduino kit, new & in the box. It seems it's time to open it..
Thanks for the help!


Robin Midgett K4IDC

On Wed, Feb 21, 2018 at 1:56 AM, Alan G4ZFQ <alan4alan@...> wrote:
My chip:

Robin,

That seems to say it all!
I describe how to reprogram that chip on the page I linked.
Or, there are instructions in this groups files.

73 aG4ZFQ




Re: Unresponsive volume control

Braden Glett
 

On Wed, Feb 21, 2018 at 12:46 am, GD wrote:
"ensure that the internal carbon part of this pot is connected to the ground pin."
Hello Geoff - very much appreciate your input. As one looks at the front of the pot, there are three prongs - which of the three is the ground pin, and which is the "internal carbon part"? (right pin, middle, or left?) Also, if it isn't connected, what should I do to connect it? 73! Brady

Re: Low Power Output - S/N 2857 - 20M

Alan G4ZFQ
 

>I suppose it could be sub-standard capacitors, does it happen on all 20m versions?

I suppose if anyone has ONLY replaced the capacitors with silver mica and got appreciably more power out then it would confirm.
I've never been certain, most others have seemed to adjust the inductors as well.

73 Alan G4ZFQ

Re: Low Power Output - S/N 2857 - 20M

Alan G4ZFQ
 

I'm going to disagree with Hans
Richard

I'm just an ignorant observer.
But it seems strange that capacitor heating is being noticed in these LPFs, standard design and components, copied through to the QRP Labs kits.
I suppose it could be sub-standard capacitors, does it happen on all 20m versions?

73 Alan G4ZFQ

In the interest of providing an alternative view,

?if you observe capacitor heating in the LPF ?

https://groups.io/g/QRPLabs/message/21483


If the capacitors get hot, It maybe because the LPF cut-off is too low?

http://qrp-labs.com/qcx/qcxtrouble.html#lowpower

Re: Low Power Output - S/N 2857 - 20M

Richard Harris <g3otk@...>
 

Hi Alan,

Many thanks for the link - I think Hans posted this after I posted about the warming up of C25/C26. I'm going to disagree with Hans that if the LPF frequency is too low then it much result in increased dissipation in the filter components. This would only occur if the currents within the filter increase significantly with, say, greater than optimum inductor values (i.e. lower cut-off frequency) and the capacitors have a significant loss component.

Richard G3OTK

On Tue, Feb 20, 2018 at 05:26 pm, Alan de G1FXB wrote:


Hi Richard,
In the interest of providing an alternative view,

?if you observe capacitor heating in the LPF ?

https://groups.io/g/QRPLabs/message/21483


If the capacitors get hot, It maybe because the LPF cut-off is too low?

http://qrp-labs.com/qcx/qcxtrouble.html#lowpower


Alan


On 20/02/2018 20:18, Richard Harris via Groups.Io wrote:
Hi Jim,

A builder of a 20m QCX mentioned that C25 and C26 (390pF) in the
output filter were getting hot when transmitting.? I had just
completed a 20m QCX and so *I checked these capacitors with an IR
thermometer and they were also warming up on transmit.*? I cut them
out and replaced with 330pF + 56pF NPO 100v ceramic capacitors
(soldered on the back of the PCB) and the output power rose
significantly? It may be worth checking these capacitors, particularly
if you have the 20m version.

Richard G3OTK


On Tuesday, 20 February 2018, 19:49, Jim - AC0OW <ars.ac0ow@...>
wrote:


As-built had power out of 1.44 watts (24vpp) at L1 out (with 50 ohm
dummy load). ?Checked resistance via L1,L2,L3 - All okay. ?Power at
BS170 drains was ~ 5 watts. ?Following fault-finding guidance, I took
2 turns off each of L1,L2,L3 and again checked continuity. ?Power went
up to 2.25 watts (30 Vpp). ?Not much improvement. ?Checked power just
prior to L1 and got 5 watts. ?So, Where should I go from here. ?Looks
like something after L1 must be loading down the Xmit chain. ?Any
suggestions would be appreciated.

Otherwise rig is great. ?Worked PJ4 for first contact. even with QRPp Hi.


Re: Unresponsive volume control

GD
 

On Tue, Feb 20, 2018 at 07:37 am, Braden Glett wrote:
I've already verified that the resistance of the control does vary when I turn it, but sadly the volume does not.
Braden, go back to this pot again and ensure that the internal carbon part of this pot is connected to the ground pin. If your soldering build is fine this connecting pin will be at ground potential but the internal component could be high if not connected to the pin.

73 Geoff G4CAO

Re: ProgRock - Serial

Alan G4ZFQ
 

My chip:
Robin,

That seems to say it all!
I describe how to reprogram that chip on the page I linked.
Or, there are instructions in this groups files.

73 aG4ZFQ

Re: QCX Broken C1

Hans Summers
 

Hi Liam
 
Now, if I lived in Tokyo and the year was around 1957, a train ride to Akihabara ........... 

If you lived in Tokyo, it wouldn't need to be around 1957. These days there is a lot of other nonsense in Akihabara, but still a lot of radio and electronics shops. You could still go there and find any part you needed. I had the luxury of spending 5.5 years working at an office in Otemachi, just a 3 minute, $1 train ride from Akihabara. Close enough that if I needed a component, I could (and frequently did) get to Akihabara and back, with browsing time in the middle, inside my lunch hour! 

Many QRP Labs kit developments started out with Akihabara components. Anyone remember the earliest of the 6-band U3 relay-switched filter kits http://qrp-labs.com/ultimatelpf ? The U3 main board and the relay board have 25mm spacing. The 2x5-way interconnect between them was a pair of identical 2x5-pin male headers installed on the PCBs, and then a pair of identical 2x5-pin female headers with their pins soldered together. It was fiddly and ugly. It was just one lunchtime when I was wandering around in Akihabara that I saw a tray of these "tall header" things, in 2x40-pin strips (easy to snap into eight 2x5-pin pieces). I just remember my jaw dropping. I rushed to the shop counter and demanded "give me a ruler, c'mon, gimme a ruler"... and yes, 25mm! it would fit perfectly! I bought all they had, and took them home and replaced them in the remaining stock of relay-switched LPF kits. So that was a beautiful solution for the interconnect problem, I never even knew those tall headers existed, until I just happened to bump into a tray of them in Akihabara. Old and the new, photos attached. Just one of many happy Akihabara memories. Alas no more... now thousands of miles away... and getting components is a matter of post, or scrounging from old TVs etc. 

73 Hans G0UPL

Re: Need help programming Ultimate 3S for relays

M0RON
 

Hi Chris, 
Check that you don't have a short in the relay board somewhere. From centre pin of bnc, or whatever you are using, to ground should be open circuit. 
Andy

Re: QCX and WSPR

Hans Summers
 

Hi Jiri

There was a bug in the WSPR encoding in the early firmware versions - some symbols in the second half of the transmission could be corrupted. This would make the transmission much less immune to QRM etc., and reduce the probability of a successful decode. So I think if you want to use the QCX for WSPR you need to be on version 1.00e. 

73 Hans G0UPL

On Wed, Feb 21, 2018 at 12:20 AM, Jiri <ok1dxk@...> wrote:

Hi Patrick,

I put my QCX 40 m into operation few days ago. Easy setup, unbelievable performance for such a little compact CW RIG. I like it very much. CW works great.

I have tried WSPR beacon too and also noticed drift of -1 ... -3. It could be caused by increasing temperature due to PA transistors heating. Although my QCX PA transistors do not heat noticeably (especially while QCX is supplied by 8V), the drift occurs.

I have no WSPR experience so I have no idea how big influence the drift has. I have little bit less spots that I would expected. Could it be due to frequency drift? Have you compared amount of WSPR spots between your WSPR equipments (QCX ant U3s)? My problem could also be (and probably more serious) an early firmware version  (1.00b) - sometimes no spots at all.

73, Jiri, OK1DXK



Dne 23.1.2018 v 0:18 patrick.nairne@... napsal(a):
I now have my QCX up and running and nicely boxed up. I have a U3s with OXCO and GPS which I use for WSPR and reports indicate very good stability with negligible drift. As the QCX has a beacon facility I have been trying that out and have received quite a number of spots on 20M. However, the drift  is bad, -3 or -4. Has anyone else noticed this, and is there any way to improve stability? Meanwhile I am working on my CW speed. A lot of CW on the bands seems very fast to me!

Patrick M0AFZ


Re: QCX and WSPR

Jiri
 

Hi Patrick,

I put my QCX 40 m into operation few days ago. Easy setup, unbelievable performance for such a little compact CW RIG. I like it very much. CW works great.

I have tried WSPR beacon too and also noticed drift of -1 ... -3. It could be caused by increasing temperature due to PA transistors heating. Although my QCX PA transistors do not heat noticeably (especially while QCX is supplied by 8V), the drift occurs.

I have no WSPR experience so I have no idea how big influence the drift has. I have little bit less spots that I would expected. Could it be due to frequency drift? Have you compared amount of WSPR spots between your WSPR equipments (QCX ant U3s)? My problem could also be (and probably more serious) an early firmware version  (1.00b) - sometimes no spots at all.

73, Jiri, OK1DXK



Dne 23.1.2018 v 0:18 patrick.nairne@... napsal(a):

I now have my QCX up and running and nicely boxed up. I have a U3s with OXCO and GPS which I use for WSPR and reports indicate very good stability with negligible drift. As the QCX has a beacon facility I have been trying that out and have received quite a number of spots on 20M. However, the drift  is bad, -3 or -4. Has anyone else noticed this, and is there any way to improve stability? Meanwhile I am working on my CW speed. A lot of CW on the bands seems very fast to me!

Patrick M0AFZ

Re: Need help programming Ultimate 3S for relays

Chris Waldrup
 

Apologies. Should say Set slot 0 for 30 meters.

Chris

On Feb 20, 2018, at 10:31 PM, Chris Waldrup <kd4pbj@...> wrote:

I mentioned I would post my results but didn’t get to it last night.
I made the changes to the filter boards and everything’s in the right order. Thanks Ken for setting me straight on that, for some reason I had thought the U3 itself got the highest band LPF but it’s fixed now and I understand.
I connected everything up, set slot 0 for 20 meter FSK so I would have a signal to check on my scope (rather than wait for WSPR).
I’m getting no RF out, regardless of the bias pot setting and the BS170 is getting hot as the manual says. I’ve swapped out with another BS170 with no change.
The 5V power line is also tied to the PA voltage pin through a jumper I added.
I didn’t get much time tonight to work on it but I will continue to investigate tomorrow night.

Chris

Re: Need help programming Ultimate 3S for relays

Chris Waldrup
 

I mentioned I would post my results but didn’t get to it last night.
I made the changes to the filter boards and everything’s in the right order. Thanks Ken for setting me straight on that, for some reason I had thought the U3 itself got the highest band LPF but it’s fixed now and I understand.
I connected everything up, set slot 0 for 20 meter FSK so I would have a signal to check on my scope (rather than wait for WSPR).
I’m getting no RF out, regardless of the bias pot setting and the BS170 is getting hot as the manual says. I’ve swapped out with another BS170 with no change.
The 5V power line is also tied to the PA voltage pin through a jumper I added.
I didn’t get much time tonight to work on it but I will continue to investigate tomorrow night.

Chris

Re: QCX Broken C1

Liam Kingsmill <lumetters1@...>
 

Alan, I didn't know QRP-LABS is a parts option.  Good info.

Hot glue may have temporarly solved the problem, but getting a healthy replacement seems the right path.

I see I put C5 in the C8 position.  So, I need a 39pF replacement for this 40 meter kit.  I'll order that item and the C1 replacement from QRP-LABS.

Jess, I've ordered from Digi-Key in the far past.  I'm on the west coast.  An outfit closer is worth looking for.

Liam



On 02/20/2018 04:51 PM, Alan de G1FXB via Groups.Io wrote:

Hi Liam,


?????? You can purchase and / or see Specification here :-)

http://shop.qrp-labs.com/SPAREPARTS/trimmer

??I'm sure you can source a substitute locally, Not sure what bricks & mortar component suppliers are on the high streets in the USA.
Does Radio Shack still trade in components, any other hobby suppliers?
Else FleaBay, Failing that Digikey, Mouser, Newark etc, etc but you pay a premium


regards Alan



On 20/02/2018 23:51, Liam Kingsmill wrote:
The variable cap C1needs replacing here.?? I broke the kit's installing it.?? (Or our puppy ate it.) Hans, might you suggest a source in the USA???
QCX Kit Serial # is 3171.
Now, if I lived in Tokyo and the year was around 1957, a train ride to Akihabara ...........??


Re: ProgRock - Serial

Robin Midgett
 

Thanks for the help, Alan. S1-3 is on (grounded) with a jumper, Tx & Rx lines are double verified.

Studying the thing tonight, I think I've found the problem. From the manual regarding firmware revisions:
pr1.01 06.Mar.2017 - Added serial interface configuration option

My chip: 

Re: LM317LZ Regulator Circuit on ProgRock

Robin Midgett
 

For the benefit of anyone reading the threads on seemingly high voltages, I decided to proceed with the build and all worked with regard to the higher voltages. 

Re: QCX Broken C1

Jess Gypin <ontarget1911@...>
 

Best sources are Digikey, Mouser and a few others.

On Feb 20, 2018, at 5:51 PM, Alan de G1FXB via Groups.Io <g1fxb@...> wrote:

Hi Liam,


?????? You can purchase and / or see Specification here :-)

http://shop.qrp-labs.com/SPAREPARTS/trimmer

??I'm sure you can source a substitute locally, Not sure what bricks & mortar component suppliers are on the high streets in the USA.
Does Radio Shack still trade in components, any other hobby suppliers?
Else FleaBay, Failing that Digikey, Mouser, Newark etc, etc but you pay a premium


regards Alan



On 20/02/2018 23:51, Liam Kingsmill wrote:
The variable cap C1needs replacing here.?? I broke the kit's installing it.?? (Or our puppy ate it.) Hans, might you suggest a source in the USA???
QCX Kit Serial # is 3171.
Now, if I lived in Tokyo and the year was around 1957, a train ride to Akihabara ...........??