Date   
Re: QCX 40 is down...

Ken Bell
 

Gents

Looking for a little more help.  I've ordered new new BS-170's and thought I'd check to make sure there isn't a problem elsewhere. 

QCX-40 Fault testing:

 

This QCX-40 worked well over the past week or so for a total power-on time of about 2-3 hours.  I’m 3-D printing a case and moved it from a prototype to a finished base and powered it up to tinker while printing the top and had no output and a ‘ratty’ continuous tone in the earpiece. 

 

Symptoms:

 

- Digital section seems OK.  Powers up and menus are normal. 

- Drawing .41 amps on power up without being keyed. Hitting the key draws .43-.44 amps

- Continuous ratty tone in earpiece on powerup with no key attached and  built-in keyer not keyed. Hitting the key silences the tone for a split second as with break-in. Level of tone varies, sometimes very loud, sometimes lower level. 
 - Checked the underside of the built-in keyer with ohm meter and key is not stuck in keyed position. Checked the keyer jack and is not shorted.

 - With antenna attached, my IC-7300 shows nothing being transmitted, whether keyed or not.  

 - On Powerup, Q2 quickly gets hot. Q1 and Q3 are very warm. 

 

 

With the above mentioned continuous tone, I do not pickup any distant stations, but if I key my IC-7300 on the same frequency as the QCX-40,  I do get additional overdriven tone in the earpiece. 

 

 

 

From the test section of the manual and website:

 

Transformer test:

Point Std Act

1 0.0 0.0

2 0.0 0.0

3 0.0 0.0

4 0.0 0.0

5 2.36 2.5

6 2.36 2.5

7 2.36 2.5

8 2.36 2.5

 

Clk1: 1.7 1.7

Clk2: 1.7 1.7

 

IC3 in RX: IC3 in TX:

RX Std Rx Act TX Std TX Act

1 5 3.08 5 sq wv            No Sq wv

2 5 3.08 5 sq wv

3 0 3.69 5 sq wv

4 0 3.5 3.3 sq wv

5 0 1.83 5

6 5 3.07 5 sq wv

7 0 0.0 0

8 5 4.9 5

9 0 3.3 0

10 0 3.5 3.3 sq wv

11 0 4.89 5

12 5 4.89 0

13 5 4.89 0

14 5 4.93 5

 

Readings don’t match on Receive. There seems to be no square wave on any of the pins using an O-Scope, so I’m stuck here looking for help. 

 


Things I've tried:

- Factory reset does nothing. 

- I’ve looked closely over the top and bottom and see nothing that has changed since it worked. 

- Checked all torrids and the Transformer.  Continuity is good through the windings to the solder joints on the back. 

 

Thank you for any assistance.... 
Ken
KN4DGR

Re: QCX-20 No power output at all

secondchancesailor
 

Well, here is another one for the sheepish ham department:   I spent more hours than I would like to admit, trying to figure out why I had no power output.   It turns out it was just a stupid mistake.  When I built the 40 meter version of this kit, I mounted all the controls on the circuit board.  When I decided to mount that radio in an ammo case, it was quite a task to remove everything.  So on the 20 meter kit I mounted all controls off the board to begin with, which included running a short piece of RG316 to an SO239.   I then covered the center conductor with some tape.    In moving the radio around, the center conductor had broken loose from the SO239 -  but I didn't know it because of the tape.   I removed the coax for now,  and mounted the BNC connector to the circuit board - and I now have 1 1/2 watts output (12 volt supply) according to an MFJ QRP wattmeter (whose accuracy is questionable).   I may see if I can improve the output a little more, but am happy to have a working radio!   Thanks to KU8H, W4JED, and KQ4TQ for the replies and suggestions!

73,
Jim W8YKG         

Re: stiff encoder? Try WD-40!

Doug W
 

Here's the whole story right from the horse's mouth
https://www.wd40.com/cool-stuff/history

Re: QCX 40 is down...

Ken Bell
 

Thank you, Michael. 

Re: #lpf Wire size for 40mtr LPF #lpf

Tony G0DDJ
 

Thanks for your help.
Tony

Re: QCX-20 No power output at all

James Daldry W4JED
 

Hi, Jim

Check for zero ohms from the center pin of the antenna jack to C29. Check for infinite ohms from the antenna jack center to ground. Both conditions must be present for the RF to get out of the radio. If there is no continuity, there probably is a lead on L1, L2, or L3 that was not sufficiently cleaned of enamel. If there is a short to ground, use a magnifying glass on both sides of the board, looking for solder strings on the bottom and wire clippings on the top.

The 5.2 watt reading at the FET drains has meaning. It means the entire transmitter chain is working. So you just have to find the road block. You're very close to having a working transmitter.

Jim Daldry W4JED

On 1/22/19 5:19 PM, secondchancesailor wrote:
My QCX-20 has no power output.  When I key down, I can hear the signal in my TS-440, and if I place a frequency counter near the PA it will read the output frequency.   But there is nothing at the RF output.

Initially, when transmitting on 7020, the output was actually on 7048.   I recently built a QCX-40 with no issues, and had to make just a very small adjustment in the reference frequency to put it on frequency.  But in this 20 meter kit, I had to set the reference frequency to 27,057,900 to get the output to match the displayed frequency - a larger error than I expected.        

So far, I have carefully checked the circuit board for any solder bridges or breaks using a magnifier hood, but found none.    Using the built-in RF Power meter to check the drains of Q1, Q2, and Q3 I read 5.2 watts, but I have read in other messages that that doesn't necessarily mean anything.   I have checked the continuity of L1, L2, and L3, and removed a couple of turns from each as has been suggested, with no change.    I can read 5.2 watts on one side of C29, but nothing on the side that goes to L3.   I pulled C29 and it measured ok, but I replaced it anyway, and still no output.     I have to admit that troubleshooting isn't really my strong suit, and I don't have much in the way of equipment.   Any help to point me in the right direction would be greatly appreciated!

Jim (w8ykg)   

Re: stiff encoder? Try WD-40!

David Wilcox
 

I don't know.  It works on so many things that Bill Meara of Soldersmoke fame dubbed it "The Popes Pee".  It works miracles!  (Toungue in cheek)

Yes, I agree...... Careful use in electronics it cab be useful.

Dave K8WPE

On Jan 22, 2019, at 10:37 AM, Rick, DJ0IP <Rick@...> wrote:

THIS IS A DISASTEROUS SOLUTION!   DO NOT DO THIS.

Ted, WD40 is a solvent and short term lubricant, and does a good job of cleaning up sticking things, but after it has worked its way clean, it should be washed out with a cleansing solvent; and then a drop of regular machine oil can be added.  What happens is, it attracts dust and any other particles in the air. These then stick to it and gum things up.   There are plenty of references to this (google). 
HERE is one:
Everybody knows WD-40 is the go-to product for silencing squeaks, displacing moisture, preventing rust, and loosening stuck parts. You probably have a can sitting in your garage right now. It has a ton of uses, but it's no panacea. In fact, there are a some jobs that the lube will absolutely ruin.
73 - Rick, DJ0IP

Re: Anyone else having trouble getting into wsprnet.org ?

Alan G4ZFQ
 

Just found another site, where you can see WSPR Data.
Frank,

There are several sites that show WSPR data and maps.
But all the data comes from WSPRnet.
They are probably a good place to look for older data because that might be downloaded just once from WSPRnet reducing the total load on that site.
This is one site that does that http://mardie4.100webspace.net/wspr/index.html it shows more statistics than you could ever want.
http://wspr.vk7jj.com/ shows maps and data, it takes real-time data from WSPRnet but tries to minimise the amount.

73 Alan G4ZFQ

Re: QCX 40 is down...

Alan G4ZFQ
 

No reception. No send.
, Q2 is hotter than a $2 pistol, but Q1 and Q3
aren't.
Ken,

It looks like there are problems.
Remove the BS170s.
Does the RX work like this?
To check everything before replacing the BS170s measure the voltages both in TX and RX mode on Q6, Q4, IC3 pin 3.

73 Alan G4ZFQ

Re: QCX 40 is down...

Michael Sharp
 

Whilst experimenting with different antennas (this is *before* I got my 4S tuner) I managed to toast my finals as well. I ended up ordering from Digikey, their p/n BS170-D27ZCT-ND. Check out www.digikey.com

-Michael

QCX 40 is down...

Ken Bell
 

Hi Guys

I've been playing around with the QCX-40 that I completed last week.  All was going well, then it stopped working. No reception.  No send.  I had a hint of the dreaded smell of magic smoke, but didn't see any.  Touching the components, Q2 is hotter than a $2 pistol, but Q1 and Q3 aren't.  From the manual, it says these should be relatively cool.  SO... I'm trying to order a replacement to see if this might be the (hopefully only) problem. There seems to be quite a plethora of BS-170 Mosfet in the T0-92 package.  Can someone give me enough info to make sure I'm ordering the right part.  Also, any other ideas as to why this might have happened. 

Re: ZM-2 toggle switches for RF

 

I have a Emtech ZM-2 and love it! No noise or clicking from the switches or power drop. Works as it should.
--
David

  N8DAH

Kit-Projects.com

Shop is now open!

Re: 10 watt amp update

Joe Cotton
 

Was it oscillating?  

Re: QCX-20 No power output at all

Bill Cromwell
 

Hi Jim,

Is your new radio drawing enough current to make that 5 watts?

If that cap is not open (apparently not, look for a short to ground beyond the cap. Is your antenna connector actually connected to the circuit board? That happened to me one time. <hanging head in shame>

73,

Bill KU8H

On 1/22/19 5:19 PM, secondchancesailor wrote:
My QCX-20 has no power output.  When I key down, I can hear the signal in my TS-440, and if I place a frequency counter near the PA it will read the output frequency.   But there is nothing at the RF output.
Initially, when transmitting on 7020, the output was actually on 7048.  I recently built a QCX-40 with no issues, and had to make just a very small adjustment in the reference frequency to put it on frequency.  But in this 20 meter kit, I had to set the reference frequency to 27,057,900 to get the output to match the displayed frequency - a larger error than I expected.
So far, I have carefully checked the circuit board for any solder bridges or breaks using a magnifier hood, but found none.    Using the built-in RF Power meter to check the drains of Q1, Q2, and Q3 I read 5.2 watts, but I have read in other messages that that doesn't necessarily mean anything.   I have checked the continuity of L1, L2, and L3, and removed a couple of turns from each as has been suggested, with no change.    I can read 5.2 watts on one side of C29, but nothing on the side that goes to L3.   I pulled C29 and it measured ok, but I replaced it anyway, and still no output.     I have to admit that troubleshooting isn't really my strong suit, and I don't have much in the way of equipment.   Any help to point me in the right direction would be greatly appreciated!
Jim (w8ykg)
--
bark less - wag more

Re: stiff encoder? Try WD-40!

Bill Cromwell
 

Hi,

My version must be right. I read it on the internet <evil grin>.

73,

Bill KU8H

On 1/22/19 5:31 PM, Alan Richmond wrote:
"The WD is for water displacing. It was used to protect ICBM missles from water condensation in the missle silos. We don;t know if there were 39 other attempts at developing it:)"
Years ago, I was told  that it was developed for the Navy; "Water Dispersant, 40 Days".
Alan
GU3ONJ
--
bark less - wag more

Re: Low RF output on QCX-30

Bill Cromwell
 

Hi Dave,

I'm a Michigan hillbilly (aka Cedar Savage) and we call that "shotgunning" parts. Just stand back and spray parts at it until it works. It's done in auto repair far too often.

73,

Bill KU8H

On 1/22/19 4:14 PM, Dave New wrote:
Alan spake:
[...]
THEREFORE THE CAPACITORS ARE AT FAULT, begin Conspiracy theory.
If find it troubling the builders do not document they they have
returned the turns count on the LPF inductors back to the proven number.
IF the capacitors were the sole contributing factor to the low power it
should not reduce the headline RF power output by returning the
inductance to the specified value(s).
[...]
In my industry (automotive), I rail at dealers that do not do an A/B/A
test, that is, they don't put the original module back in to see if the
'bad module' makes the issue come back. Thus, I get a lot of TNF
(Trouble Not Found) returns, when the original issue was likely a wiring
or connector fault, that was cured when the wiring was disturbed or the
connectors cycled when the module swap took place.
Sigh. Everyone is in too much of a hurry to get the customer back on
the road, or in the case of radio troubleshooting, to button it up and
put it back on the air. It does a disservice to those that really could
use the true root cause instead of "I Easter-egged these components, and
it works, so that must have been it!"
73,
-- Dave, N8SBE
--
bark less - wag more

Re: Anyone else having trouble getting into wsprnet.org ?

Frank - DB1FW
 

Just found another site, where you can see WSPR Data. 

http://www.dxplorer.net/wspr/tx/

Frank
--
Frank - DB1FW

Re: Anyone else having trouble getting into wsprnet.org ?

geoff M0ORE
 

I think it is very unfair to complain about a site such as WSPR.net on a forum such as this. If you have purchased software  and had poor service, then you have a right to complain. WSPR and similar digital modes like FT8 are free software that Joe and possibly a team have spent thousands of hours developing and then giving the amateur serice free use. Commercial companies would spend thousands of pounds/dollars/ what ever your currency is to get software as comprehensive as these digital signal processors.
A large number of amateurs download free software for their own use with no thought about how much time has gone into the developement of that program. How many have spent just a few moments to send the author a short email to say "Thank you ".
I admit that I am guilty of this but with some programs that I use frequently, I have been in contact with the authors and they have been grateful of the recognition they deserve.

Re: stiff encoder? Try WD-40!

Alan Richmond
 

"The WD is for water displacing. It was used to protect ICBM missles from water condensation in the missle silos. We don;t know if there were 39 other attempts at developing it:)"

Years ago, I was told  that it was developed for the Navy; "Water Dispersant, 40 Days". 

Alan
GU3ONJ

QCX-20 No power output at all

secondchancesailor
 

My QCX-20 has no power output.  When I key down, I can hear the signal in my TS-440, and if I place a frequency counter near the PA it will read the output frequency.   But there is nothing at the RF output.

Initially, when transmitting on 7020, the output was actually on 7048.   I recently built a QCX-40 with no issues, and had to make just a very small adjustment in the reference frequency to put it on frequency.  But in this 20 meter kit, I had to set the reference frequency to 27,057,900 to get the output to match the displayed frequency - a larger error than I expected.        

So far, I have carefully checked the circuit board for any solder bridges or breaks using a magnifier hood, but found none.    Using the built-in RF Power meter to check the drains of Q1, Q2, and Q3 I read 5.2 watts, but I have read in other messages that that doesn't necessarily mean anything.   I have checked the continuity of L1, L2, and L3, and removed a couple of turns from each as has been suggested, with no change.    I can read 5.2 watts on one side of C29, but nothing on the side that goes to L3.   I pulled C29 and it measured ok, but I replaced it anyway, and still no output.     I have to admit that troubleshooting isn't really my strong suit, and I don't have much in the way of equipment.   Any help to point me in the right direction would be greatly appreciated!

Jim (w8ykg)