Date   

Re: Group storage

Alan Richmond
 

Is the cost of extra storage a one-off cost, or an annual one?

Alan

GU3ONJ


E & O E


Re: RX Module - I/Q balance question #rcvr

Lexa, OK1DST
 

Hi Erik,
great idea to go w/o output transformers! I will try asap.
And I was not sure if I can get output with only one channel, it is new to me and also good to check!

Thanks for now and I will report later on....
73
L. -dst-


Re: RX Module - I/Q balance question #rcvr

Alan G4ZFQ
 

I am not able to perform automatic I/Q balance with my RX module and looking for any advices/experiences. I am quite sure I made T3 correctly with correct orientation and phasing (as unit seems to produce correct I/Q signals). I do not know if there can be some other source of so big phase/gain shift to be out of range of this automatic algorithm in CW skimmer or...?
Lexa,

Perhaps you could do Eric's modifications https://groups.io/g/QRPLabs/message/30208

unit seems to produce correct I/Q signals
I wonder why do you say that?
Skimmer has a very good phasing system, I would expect some sort of balancing to show even with the cheap transformers.
If Eric's modifications do not help check all voltages on the ICs. If there are large variations it may point to a fault.

73 Alan G4ZFQ


Re: RX Module - I/Q balance question #rcvr

Erik Kaashoek
 

I'm also using the RX module as a SDR rx either standalone or as the IF for higher frequencies
This is what I did, it may help you or not.
First check you have actually I AND Q output. If one channel is not working you will get output but many "ghosts" 
I removed the output transformers. There where big frequency dependent amplitude differences between the two transformers and I was unable to get to acceptable phase/amplitude balance.
I also remove the filter capacitors (R3-R6) and replaced them with 2.2nF capacitors to get a more flat output, minute differences between the original capacitors again made balancing the whole audio band impossible.
--
Erik@Home


Re: Prog Rock board voltages

Alan G4ZFQ
 

I did, and got +5.3V, and +3.7V, at the locations specified. Are these within spec?  And, if not, what needs correcting?
Hans has said before that the voltages are somewhat higher than nominal. I'm not sure about measuring resistances when fitted, other paths might be involved. If you use the formula for the regulator it comes out at around 5.15V. The 3V3 also calculates at around 3.6 so your readings are as expected.

73 Alan G4ZFQ


Re: I Burned Up My U3S

Hans Summers
 

Hi Mike


73 Hans G0UPL 

On Sun, Jan 27, 2019, 01:02 n0mpm <morgamp52@... wrote:
So even after I wrote myself a note to use 5volts on my new U3S, I got excited and cooked it with 12v !!
I know the ATMega is cooked, but wondering if everything else may be OK...I hope the 3.3 voltage regulator saved the Si5351A, and I checked out the LCD and it survived.
Questions:
1.  What else may be a gonner?
2.  I have a spare ATMega from a QCX.  Can I reflash it for the U3S or are the code plugs different?

At least I have plenty of snow to shovel to keep me busy if I have to order parts!
Mike. 


Re: I Burned Up My U3S

@CurtisM
 

Mike

I built a faulty power supply, and in my case only the controller was zapped. Research my call here to find Hans reply. I ended up ordering a spare basic kit to have spare parts, as well as a programmed controller. Of course if you have the right IC and tools, go for it.

Curt


Re: I Burned Up My U3S

Curt M.
 

Ugh....I think you just convinced me to install a little buck board inside of my U3S. I have a U3S that I use as a 5w beacon that requires 13.8v and I now have (2) QCX’s that are also powered with 13.8v. I have to keep telling myself to be careful with the other U3S that I use for WSPR and QRSS that runs on 5v because I’ll smoke it if I plug in one of the cables without the buck board on it. 

So if it’s any consolation you may have at least helped someone out. Hopefully you’ll be able to get yours back up and running. 

Curt M.


Re: Prog Rock board voltages

KI7MWA
 

Measuring R1 and R2, in the board, I'm getting 0.968kOhms and 2.82KOhms, which, should be giving me 1.25V(1+(2.82/0.968)) = 4.89V.  But I'm not good enough at reading schematics to conclude whether or not my measurements are being affected by some other part of the circuit (e.g. the LM317LZ).

I'm inclined to try adding some parallel resistance to R2, just to see if I'm understanding the voltage regulator part of the circuit.


RX Module - I/Q balance question #rcvr

Lexa, OK1DST
 

Hi friends,
I just finished Reciever module with ProgRock kit as LO.

My intention now is to use it as SDR rx for IF output from my K3 and TS-850 and use with CW skimmer.

So I have LO on 8.195x4, rf input directly to T3 (w/o band-pass filter) and cennected I/F out from K3 - everything seems to be OK.
CW skimmer is decoding signals but there are some "ghosts" from opposite sideband. Need for I/Q balance adjustment.
I jump into I/Q balance window (as part of CWSkimmer application) and no data there :-(  (there are empty graphs for phase/gain).

So I tried to connect PM-SDR unit (same levels, same input frq etc,, same cabling and sound card for I/Q,...) and I can see data plots in Phase/Gain graphs and calculated balance. And traces on CW skimmer are w/o ghosts and all is perfect.

So at summary - I am not able to perform automatic I/Q balance with my RX module and looking for any advices/experiences. I am quite sure I made T3 correctly with correct orientation and phasing (as unit seems to produce correct I/Q signals). I do not know if there can be some other source of so big phase/gain shift to be out of range of this automatic algorithm in CW skimmer or...?

Thanks for any advice...
73!
Lexa, ok1dst


Re: Got my QCX 40 working but very low volume in the headphones

Don Huffstetler <wa6ouw@...>
 

It was aligned by a great builder

Don



-----Original Message-----
From: Chopper <bob@...>
To: QRPLabs <QRPLabs@groups.io>
Sent: Sat, Jan 26, 2019 2:09 pm
Subject: Re: [QRPLabs] Got my QCX 40 working but very low volume in the headphones

When you went through the alignment procedures, did you get the expected max or min values or just the highest and lowest points. 


Re: Got my QCX 40 working but very low volume in the headphones

N3MNT
 

When you went through the alignment procedures, did you get the expected max or min values or just the highest and lowest points. 


Re: Group storage

N3MNT
 

QUOTE" Put it on imgur.com.

Link to graphic.  Like this: https://i.imgur.com/pj8eVJS.png"

I am not a fan of this as I would never open this tiny url type link as way too many contain viruses


I Burned Up My U3S

n0mpm
 

So even after I wrote myself a note to use 5volts on my new U3S, I got excited and cooked it with 12v !!
I know the ATMega is cooked, but wondering if everything else may be OK...I hope the 3.3 voltage regulator saved the Si5351A, and I checked out the LCD and it survived.
Questions:
1.  What else may be a gonner?
2.  I have a spare ATMega from a QCX.  Can I reflash it for the U3S or are the code plugs different?

At least I have plenty of snow to shovel to keep me busy if I have to order parts!
Mike. 


Prog Rock board voltages

KI7MWA
 

The assembly manual, page 10, says "If there is any problem with the measured voltages then you have GOT to investigate and find the problem before going any further!." 

I did, and got +5.3V, and +3.7V, at the locations specified. Are these within spec?  And, if not, what needs correcting?

I built according to section 4.3.1, with the LM317LZ on the Prog Rock board, not on the Synth board.  I did screw up, however, and had to purchase a replacement LM317LZ.

My supply voltage is +9V

Thanks


Got my QCX 40 working but very low volume in the headphones

Don Huffstetler <wa6ouw@...>
 

QRPers

I got my QCX-40 up and running, but the volume on the listening seems to be very low.

Even with my gain turned all the way up, I must listen closely to hear anything using headphones.......... 

and it is not enough to drive a small speaker like the Kenwood KES-3

ANY IDEAS?

Don
wa6ouw
Redding, Ca


Re: Stuck at single line #qcx #problem

James Daldry W4JED
 

Hi, Jim

You'll need to get the eeprom file from Hans. Also, of course, make sure the "fuses" are correct.

Jim W4JED

On 1/26/19 3:53 PM, jstratigos@... wrote:
Searching the group it looks like others have had similar problems with rev 4 and t1.00e or f. The chip acts like it is not programmed. I tried flashing the T1.00.hex into the original chip in situ using a USBTIny programmer with QCX board powered by the programmer. It flashed and verified without error but now I get the dreaded "use original chip" message! Looks like I may need a Hans consultation!

Jim - WB4HYY


Re: QCX 20 No output...New build

James Daldry W4JED
 

Hi, Paul

Q6 either is open, its collector is shorted to ground, or both. Check for zero ohms to ground from the collector. It should check open. If short, you either have a "whisker" short or one or more shorted FET's. If the collector reads shorted to ground pull the FET's and see if the short goes away. Once the short is cleared you'll need to replace Q6.

Jim W4JED

On 1/26/19 3:19 PM, paul.hadfield@... wrote:
This is the first kit of any kind I have built and everything has been a vertical learning curve.
On completion everything appears to work as expected just no power out.
I have checked continuity and re soldered all toroids, and they are fine.
Using the built in power meter I have checked for output at Q1,2 and 3 as suggested in the manual. No output at these points.
Having spent most of Saturday afternoon searching through posts to point me in the right direction I have been looking at the voltages with Q6.
Now I think something is wrong here but but not sure, and don't know where to begin correcting the situation if it is wrong.
Using the built in V meter I am seeing
Pin1 Emmiter , 11.45v key on or off
Pin2 Base, 11.1v key off and 7.46v keydown
Pin3 Collector 0v key on or off.

Any help would be appreciated as I would love to get it all working 100%

Paul


Re: Stuck at single line #qcx #problem

Jim
 

Searching the group it looks like others have had similar problems with rev 4 and t1.00e or f. The chip acts like it is not programmed. I tried flashing the T1.00.hex into the original chip in situ using a USBTIny programmer with QCX board powered by the programmer. It flashed and verified without error but now I get the dreaded "use original chip" message! Looks like I may need a Hans consultation!

Jim - WB4HYY


QCX 20 No output...New build

Paul
 

This is the first kit of any kind I have built and everything has been a vertical learning curve.
On completion everything appears to work as expected just no power out.
I have checked continuity and re soldered all toroids, and they are fine.
Using the built in power meter I have checked for output at Q1,2 and 3 as suggested in the manual. No output at these points.
Having spent most of Saturday afternoon searching through posts to point me in the right direction I have been looking at the voltages with Q6.
Now I think something is wrong here but but not sure, and don't know where to begin correcting the situation if it is wrong.
Using the built in V meter I am seeing
Pin1 Emmiter , 11.45v key on or off
Pin2 Base, 11.1v key off and 7.46v keydown
Pin3 Collector 0v key on or off.

Any help would be appreciated as I would love to get it all working 100%

Paul