Date   

Re: Horizontal lines after power up

Jim Netwal
 

I am now convinced that I have a bad screen.  I took the screen from the QCX 40 and put it on the QCX 20 and it seems to be working fine.  I was able to do the alingment on the radio and I am receiving signals.  It's been on for more than an hour now and it's working fine.  So now the questions is where can I order a new screen from here in the US?

Thank you!
Jim W9UUM


Re: BPF too good? #filter

Dave
 

Toroids are self shielding, as almost all the magnetic flux is enclosed in the toroid.  There may be some capacitive linkage to the nearby metal, but it would be very minimal.

Dave


On Tue, Jul 7, 2020 at 4:48 PM Jim Painter via groups.io <Jfpainter=yahoo.com@groups.io> wrote:
It looks like your test jig has two large metal brackets which are very close to the coils. Could they be screwing with the inductance? 


Jim...kq3s



On Tue, Jul 7, 2020 at 9:02 AM, Bob Benedict, KD8CGH
<rkayakr@...> wrote:
I built a 20 m BPF. Since I have many to make, I made a holder with SMA connectors and decided to use my recently acquired  NanoVNA for the first time with a filter. Filter analysis shows a center at 14.09 MHz and a 3 db BW of 1.39 MHz, which seems fine. Neither variable cap is at its extreme.
My concern is that the loss looks too low. I'm seeing 0.4 dB S21 loss. The VSWR is also 2. After calibration check with straight through wires scan reads VSWR 1.03, return loss -35 dB and S21 gain -.077 dB.




--
  73
    KD8CGH


Re: For Sale: QRP Tuner

rtharp0001@...
 

The tuner has sold. 

73
Robert

On Tue, Jul 7, 2020 at 2:23 PM rtharp0001 via groups.io <rtharp0001=gmail.com@groups.io> wrote:
Emtech ZM-2  QRP Z-match Tuner with BNC connectors, like new condition. Maximum power is 15 watts. Perfect match for QCX or QSX.  Contact direct at rtharp0001@... for pictures or more information.  $80 with free shipping to CONUS, PayPal only. 


Re: BPF too good? #filter

Jim Painter
 

It looks like your test jig has two large metal brackets which are very close to the coils. Could they be screwing with the inductance? 


Jim...kq3s



On Tue, Jul 7, 2020 at 9:02 AM, Bob Benedict, KD8CGH
<rkayakr@...> wrote:
I built a 20 m BPF. Since I have many to make, I made a holder with SMA connectors and decided to use my recently acquired  NanoVNA for the first time with a filter. Filter analysis shows a center at 14.09 MHz and a 3 db BW of 1.39 MHz, which seems fine. Neither variable cap is at its extreme.
My concern is that the loss looks too low. I'm seeing 0.4 dB S21 loss. The VSWR is also 2. After calibration check with straight through wires scan reads VSWR 1.03, return loss -35 dB and S21 gain -.077 dB.




--
  73
    KD8CGH


Re: QCX+ order date.

Ron W3ZV
 

Got what I needed. Thanks

Ron W3ZV

On July 7, 2020 at 16:17:17, Ron W3ZV via groups.io (w3zv.radio@...) wrote:

Would some kind person who received their QCX+ within the last couple of days provide their order date to me (by direct email) so I can get a rough idea of where I stand on the list.. Thanks

Ron W3ZV
w3zv.radio@...
 

--
Ron W3ZV

--
Ron W3ZV


QCX+ order date.

Ron W3ZV
 

Would some kind person who received their QCX+ within the last couple of days provide their order date to me (by direct email) so I can get a rough idea of where I stand on the list.. Thanks

Ron W3ZV
w3zv.radio@...
 

--
Ron W3ZV


For Sale: QRP Tuner

rtharp0001@...
 

Emtech ZM-2  QRP Z-match Tuner with BNC connectors, like new condition. Maximum power is 15 watts. Perfect match for QCX or QSX.  Contact direct at rtharp0001@... for pictures or more information.  $80 with free shipping to CONUS, PayPal only. 


Re: BPF too good? #filter

Bob Benedict, KD8CGH
 

I suspected the cal also. When I repeated a sweep with the wires I used for "through" I got what I listed above - almost perfect cal for 10 MHz to 30 MHz:
VSWR 1.03, return loss -35 dB and S21 gain -.077 dB.
As stated in OP - this is my first try at measuring a filter with the NanoVNA, I would not be surprised to find a measurement error obvious to others well versed.
--
  73
    KD8CGH


Re: BPF too good? #filter

ajparent1/KB1GMX
 

I'd be suspect of the cal.   If the cables and jig called at 20M the loss should
be zero and the SWR  also perfect (cal absorbs errors).

The S11 should be a good match inside the pass band, its a symmetrical
filter.

For S21 its too good.  I can imagine and model a better filter loss but
only with perfect caps and coils.  See ELSIE.

1.25Db is best I could ever do for double tuned and that was with
3/8th" ceramic slug tuned inductor ( with enough turns to keep
core barely inserted) with silver mica caps critically coupled.

That was verified with both VNA (agilent 8573) NanoVNA, and
S11/S21 setup on Rigol DSA815T.  I tend to do that want I get
numbers close to the book.  I have found the NanoVNA I have
to be a bit more optimistic at HF by variable amounts but under
.1db (good enough).

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


Re: 40 Meter QCX Si5351 Error

Ronald Taylor
 

Paul, check that you got the orientation of the two diodes D1 and D2 correct and look for about 3.5 or so volts on the cathode of D1. If that is good, check your connections at R3 and R4 as well as pins 27 and 28 of the microcontroller. If they look good, check continuity (with power off) between pin 28 and R4. hold one meter lead on pin 28 and move the other to each side of R4. You should see 1K ohm on one lead and zero ohms on the other. Likewise do the same between pin 27 and R3. These connections are the I2C communication buss between the microcontroller and the Si5351a. 

Report back on what you find ... 73 ... Ron

On Tue, Jul 7, 2020 at 8:07 AM K2DB Paul Mackanos <paul.mackanos@...> wrote:
I had a bad intermittent power connection, i moved the QCX and the power went on and off several times due to the loose connector.
Now all I get is the start up screen then it goes to Si 5351 Error.
Have no idea where to start.
Paul K2DB


Re: BPF too good? #filter

Dave
 

I would have to guess who LeBron James is and know well who David Beckham is. And Victoria too. :-)

Dave


On Jul 7, 2020, at 11:51, Bob Benedict, KD8CGH <rkayakr@...> wrote:

Thanks for the vote of confidence. What gives me pause is that the docs list the insertion loss as 1.75 dB. While it is not impossible that I built one of Hans's filters with a lower loss than he did, I think the probability is about like that of me outplaying LeBron James in basketball (or like outplaying Beckham in football for those of you in the rest of the world).
--
  73
    KD8CGH


Re: BPF too good? #filter

Bob Benedict, KD8CGH
 

Thanks for the vote of confidence. What gives me pause is that the docs list the insertion loss as 1.75 dB. While it is not impossible that I built one of Hans's filters with a lower loss than he did, I think the probability is about like that of me outplaying LeBron James in basketball (or like outplaying Beckham in football for those of you in the rest of the world).
--
  73
    KD8CGH


Re: QCX Semi QSK locks tx ON .

ian liston-smith
 

Thanks for the suggestions everyone.

I've had another look at this fault and as suggested, Q6 was blown. I found a nearish equivalent in a TO39 case that I fitted under the board. It fixed the original semi-QSK locked into transmit fault, but now the rig doesn't switch to receive unless one of the three controls is pressed one or twice. It works perfectly ok in full QSK.

The replacement transistor I used was a 2N4033, but I tried 2N4036 and a few other PNP transistors with the same result.

Is there something very specific about the Q6 MPS751, or do I have another fault lurking?

All these tests were into a dummy load.

Thanks.

Ian G4JQT


Re: 40 Meter QCX Si5351 Error

Roger Hill
 

Hi Paul

maybe start here: https://www.qrp-labs.com/qcx/qcxtrouble.html


73

Roger

G3YTN

---
***************************
Roger Hill
***************************


On 2020-07-07 11:07, K2DB Paul Mackanos wrote:

I had a bad intermittent power connection, i moved the QCX and the power went on and off several times due to the loose connector.
Now all I get is the start up screen then it goes to Si 5351 Error.
Have no idea where to start.
Paul K2DB


40 Meter QCX Si5351 Error

K2DB Paul Mackanos
 

I had a bad intermittent power connection, i moved the QCX and the power went on and off several times due to the loose connector.
Now all I get is the start up screen then it goes to Si 5351 Error.
Have no idea where to start.
Paul K2DB


Re: BPF too good? #filter

Dave
 

Looks to me as if the filter is perfect.  Well done and may all your filters work exactly as designed!

Dave


On Jul 7, 2020, at 09:02, Bob Benedict, KD8CGH <rkayakr@...> wrote:

I built a 20 m BPF. Since I have many to make, I made a holder with SMA connectors and decided to use my recently acquired  NanoVNA for the first time with a filter. Filter analysis shows a center at 14.09 MHz and a 3 db BW of 1.39 MHz, which seems fine. Neither variable cap is at its extreme.
My concern is that the loss looks too low. I'm seeing 0.4 dB S21 loss. The VSWR is also 2. After calibration check with straight through wires scan reads VSWR 1.03, return loss -35 dB and S21 gain -.077 dB.

<20mBP.jpg>
<holder.jpg>



--
  73
    KD8CGH


Re: Horizontal lines after power up

Arv Evans
 

Jim

Horizontal lines would seem to indicate that one of the data (DB) leads 
is not making a good connection.  If you can turn the contrast down so 
you can see individual bit positions on a vertical line of dots you may 
be able to see which bit is not failing.  From this you could discern 
which lead (DB-0 thru DB-7) is not working.  That would tell you which 
wire to check.  


This all assumes that you are using either a 2-line or 4-line LCD display.
If using some other display then it might take more detective work to 
find the missing bit(s).  

Arv
_._


On Mon, Jul 6, 2020 at 9:50 PM Jim Netwal <w9uum732u@...> wrote:
I'm thinking now that I may have a bad display.  I've checked all connections and and reheated all solder joints to the display and micro controller.  I have a QCX 40 as well so I put the "bad" display in it and same lines on that radio.  I haven't tried the "good" screen on the QCX 20 yet in case I caused the problem.  Also adjusting R47 voltage 0 - 5 volts is good.

Jim W9UUM


Re: Shipping Estimate for QCX+

Mark W
 

Thank you Hans.


Re: Shipping Estimate for QCX+

Hans Summers
 

Hi Mark

We are working through the backlog but there were nearly 600 pre-orders and it is taking some time to pack them and ship them all. I put this update on the QCX+ page http://qrp-labs.com/qcxp too this morning. 

By default we are shipping them out in chronological order but if anyone has any specific request they can email me. 

73 Hans G0UPL
http://qrp-labs.com

On Tue, Jul 7, 2020 at 5:15 PM Mark W <K3MRK1@...> wrote:
Is there an estimate on when the QCX+ will be shipping? My order said PRE-ORDER, but no info on when they would be available.
Thanks
Mark
K3MRK


Shipping Estimate for QCX+

Mark W
 

Is there an estimate on when the QCX+ will be shipping? My order said PRE-ORDER, but no info on when they would be available.
Thanks
Mark
K3MRK