Date   

Re: QCX mini: RF output BNC or SMA #poll-notice

Arv Evans
 

I was joking about using ladder line.    8-)

Arv
_._



On Sun, Aug 9, 2020 at 1:52 PM ajparent1/KB1GMX <kb1gmx@...> wrote:
And the mission is?

At home using ultra compact radio.
Occasional portable, no long trek, may even use a cart for transport.
Some trek where supplies, weight, and space compete.

Ladder line is clumsy and awkward to deploy in the field and requires
a tuner and maybe a balun.  No typical connector, likely binding posts.
At home it will try to pull or flip what its connected to due to "spring" in
the wire.

RG174, 20M of it?  The likely compact portable user will take maybe
5-8M of it.  I hate it as its fragile.  many use it as its cheap.  Typical
connector is BNC, maybe RCA.

RG316 has the same loss,  higher price tag but much more rugged.
Even then likely a short peice.  BNC, maybe SMA.

RG58C/u  or better yet LMR190-flex as you want it easy to coil and 
have some flex.  Loss is not all that bad at 20M for 20M (66ft!).
Most would carry 8-10M of it.  BNC is the usual, maybe PL259.

Typical field setup I use is radio, RG316 jumper of 1-2ft, T1 tuner if needed
then RG58C/u to antenna.  IF end fed half wave, no T1 and jumper.
Connectors usually BNC as T1 tuner uses that.

For high power (100W) semi portable VHF, then RG8X/LMR240 
up to 15M of cable is reasonable for 6 and 2m.  The antenna is a 50ohm 
yagi usually collapsible.  For HF same cable but End Fed half wave for
40/20 or 10m.  mix of BNC, PL259 or N and occasional SMA.

Field day, we build a station in the field and its elaborate and no
consideration for compact radio, cable, or power.  Just sayin.


Allison
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Re: Encoder type/mfgr. QCX?

ajparent1/KB1GMX
 

The usual issue with many of those encoders is they can be one of
several codes and the rate in pulses per revolution is much higher
than the encoder used.  The difference is in the range of less than
90 per revolution to some of the Bornes at 400pulses revoution.

The latter encoders at 200P/R and higher need a much more responsive
program usually interrupt driven.  if not it just does flaky things.  If
your doing your own code that is generally not an issue,  For QCX you
can't (sources not available).  For someone else design the pins
needed (for interrupt interface) may already be claimed.  That
makes coding awkward.

A optical version of the typical QCX and similar encoder is
common and cheap buy spares.  Simply dropping something
else in without code work is not often successful.

Allison
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Re: 0.03w RF output, 1w at transistor drains, Help? #qcx

scot forshaw
 

I’d order another Cap and check Q6 output at L4 also. Q6 can be problematic.

Hans sells the caps or get a complete LPF kit from him they are cheap enough.

2E0WWV
Scot

On 9 Aug 2020, at 20:24, Ben <ben@...> wrote:


Re: QCX mini: RF output BNC or SMA #poll-notice

ajparent1/KB1GMX
 

And the mission is?

At home using ultra compact radio.
Occasional portable, no long trek, may even use a cart for transport.
Some trek where supplies, weight, and space compete.

Ladder line is clumsy and awkward to deploy in the field and requires
a tuner and maybe a balun.  No typical connector, likely binding posts.
At home it will try to pull or flip what its connected to due to "spring" in
the wire.

RG174, 20M of it?  The likely compact portable user will take maybe
5-8M of it.  I hate it as its fragile.  many use it as its cheap.  Typical
connector is BNC, maybe RCA.

RG316 has the same loss,  higher price tag but much more rugged.
Even then likely a short peice.  BNC, maybe SMA.

RG58C/u  or better yet LMR190-flex as you want it easy to coil and 
have some flex.  Loss is not all that bad at 20M for 20M (66ft!).
Most would carry 8-10M of it.  BNC is the usual, maybe PL259.

Typical field setup I use is radio, RG316 jumper of 1-2ft, T1 tuner if needed
then RG58C/u to antenna.  IF end fed half wave, no T1 and jumper.
Connectors usually BNC as T1 tuner uses that.

For high power (100W) semi portable VHF, then RG8X/LMR240 
up to 15M of cable is reasonable for 6 and 2m.  The antenna is a 50ohm 
yagi usually collapsible.  For HF same cable but End Fed half wave for
40/20 or 10m.  mix of BNC, PL259 or N and occasional SMA.

Field day, we build a station in the field and its elaborate and no
consideration for compact radio, cable, or power.  Just sayin.


Allison
-------------------------------
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Re: QCX mini: RF output BNC or SMA #poll-notice

Arv Evans
 

Maybe 450 ohm ladder line would be even more efficient.
The Problem with that is the QCX-mini is narrower than the ladder line.

Arv
_._


On Sun, Aug 9, 2020 at 1:17 PM The Crunchbird <pulsedevil@...> wrote:
There is a price to pay for the lightweight RG174 cable and that is in the power that your antenna receives. For a 20 meter length of RG174 the loss is 1.366dB so for 5 Watts output from your transmitter, the antenna will receive only 3.65 Watts. Compare this to RG58 where the loss for the same length is 0.611dB and 4.344 Watts will be delivered to the antenna. 

On Sun, Aug 9, 2020 at 5:30 AM <namerati@...> wrote:
On Fri, Aug 07, 2020 at 10:17:14PM +0000, Graham, VE3GTC wrote:
>This is has been an interesting discussion.
>
>Besides SMA and BNC, the TNC and RCA connector has been mentioned but in
>reality there are many more good choices.
>
>For example, the FME connector ( FME - For Mobile Equipment ), good to
>several GHz, PCB mount, bulkhead mount, size not too much bigger than RG-58
>cable, and not very expensive.

That's also an option, though the MCX PCB mount jacks that I have share
the same footprint as SMA PCB mount jacks, so in that case users would
have an option of either one. I don't know if that's true for FME, which
is just obscure enough that my local supplier doesn't carry FME PCB
mount jacks.

Additionally, FME connectors look to be for RG58/59 cable, and as this
is a *mini* and *ultra-portable* transceiver I would probably end up
using RG174.

No sense in carrying 300 grams worth of cable when 30 grams will do!

>There is also the mini UHF connector, also good to several GHz, PCB mount,
>bulkhead mount,.

Nice but, again, obscure enough that my "supplier of reference" doesn't
carry much along those lines.

SMA and MCX seem widely available (not to mention RCA...) -- if we are
going for obscure connectors then we might as well add APC3.5
(SMA-compatible but robust) or Lemo 00 NIM-CAMAC (tiny and super-robust,
as well as super-expensive) to the mix...





Re: 0.03w RF output, 1w at transistor drains, Help? #qcx

Ben
 

For measuring capacitors and inductors I have recently bought the Peak LCR45. Really like it. With this meter I found that I had fried my C25 and C26. You can buy a replacement part to be sure, or buy a meter to verify I guess?

Regarding the 5.2W. I found the source: https://www.qrp-labs.com/qcx/rfpower.html

Quote:
The scaling of the resistors R56 and R58, which form a potential divider, is such that the maximum reading from this RF power meter is 5.2W. If you see 5.2W on the screen, it means "anything from 5.2W and up". You maxed out the processor's Analog to Digital Converter input. 


Re: QCX mini: RF output BNC or SMA #poll-notice

The Crunchbird
 

There is a price to pay for the lightweight RG174 cable and that is in the power that your antenna receives. For a 20 meter length of RG174 the loss is 1.366dB so for 5 Watts output from your transmitter, the antenna will receive only 3.65 Watts. Compare this to RG58 where the loss for the same length is 0.611dB and 4.344 Watts will be delivered to the antenna. 

On Sun, Aug 9, 2020 at 5:30 AM <namerati@...> wrote:
On Fri, Aug 07, 2020 at 10:17:14PM +0000, Graham, VE3GTC wrote:
>This is has been an interesting discussion.
>
>Besides SMA and BNC, the TNC and RCA connector has been mentioned but in
>reality there are many more good choices.
>
>For example, the FME connector ( FME - For Mobile Equipment ), good to
>several GHz, PCB mount, bulkhead mount, size not too much bigger than RG-58
>cable, and not very expensive.

That's also an option, though the MCX PCB mount jacks that I have share
the same footprint as SMA PCB mount jacks, so in that case users would
have an option of either one. I don't know if that's true for FME, which
is just obscure enough that my local supplier doesn't carry FME PCB
mount jacks.

Additionally, FME connectors look to be for RG58/59 cable, and as this
is a *mini* and *ultra-portable* transceiver I would probably end up
using RG174.

No sense in carrying 300 grams worth of cable when 30 grams will do!

>There is also the mini UHF connector, also good to several GHz, PCB mount,
>bulkhead mount,.

Nice but, again, obscure enough that my "supplier of reference" doesn't
carry much along those lines.

SMA and MCX seem widely available (not to mention RCA...) -- if we are
going for obscure connectors then we might as well add APC3.5
(SMA-compatible but robust) or Lemo 00 NIM-CAMAC (tiny and super-robust,
as well as super-expensive) to the mix...





Re: Encoder type/mfgr. QCX?

Jack Margolis
 

I didn't think that encoder technology was going to be rocket science, but electromechanical gadgets can be a headache, at times.   I did put 10k resistors from 5V to A and B and LEDs to ground from the same points.  Turning the shaft gets the usually blinking that alternates to a degree and proves that the unit is working. 

Thanks for the help and advice on this.    Right now, I have to find a replacement for the encoder that I took from an OCX kit that is unbuilt. 
I should at least build the power supply and plug in the mpu and LCD to see if the encoder will work.  This is an older kit that I want to build after I buy a QCX+ and get it going. 
That way I can do the mods to the old one using the new one as a reference.
JACK


Re: 0.03w RF output, 1w at transistor drains, Help? #qcx

 

I was not able to get a dummy load, however I used an antenna that i've tuned to be very close to 50ohm

The 5.2w was at the Drains, instead of the gates I measured no power at the gates. all the soldering looks fine, and all the finals have no visual markings on them at all

After removing c25 and c26 from the board to test them, it appeard that c26 has a small crack in it, however it appears to measure correctly for continuity and resistance, i am unsure about its true capacitance as i do not have a capacitance meter
I do not have another 391 capacitor, what can i do now?


Re: QSO Today Virtual Ham Radio Expo - 08/09 August

R. Tyson
 

Hi Ross,

It does download the app, but you don't need it. You can just click on "view in browser".
The view in browser link is hidden.  Here's how to do it.

Go to https://zoom/us

Click on           Join meeting.

Enter the 3 blocks of numbers for the zoom meeting.

The next screen has  2 messages in a line.....

 If you have zoom client installed launch meeting  Otherwise download and run zoom


The words       launch meeting      are in blue and you can click on them. After that and below those two messages you will see        join from your browser        the join from your browser is blue and clicking on that will take you through to the next stage.

It is simple to just use your browser to access zoom meetings, you do not need the app.
If the app is automatically downloaded then just empty it back out of the downloads folder later on.

Reg                             G4NFR


Re: QSO Today Virtual Ham Radio Expo - 08/09 August

Ross Wilson
 

Hans,

Maybe it's different if you are in North America or Europe, but I'm trying to join the meeting from Australia and no matter what I do I'm prompted to download the app.

Ross AC3DN


On Sun, 9 Aug 2020, 21:03 Hans Summers, <hans.summers@...> wrote:
Hello all

Thanks, it was nice to chat to so many of you yesterday! 

For those that could not attend - the shack tour was in fact recorded so I am going to see if I can get it on YouTube then people can watch it there. 

The expo chat room is open all day and so feel free to drop in there, it supports keyboard chat, voice chat and video chat. The ZOOM video conference is also open all day see http://qrp-labs.com/zoom

Meeting ID: 838 2352 7803
Passcode: 299230
Link to meeting: https://www.zoom.us/join

Note that you do NOT need a Zoom account to join the zoom meeting. You do not need to provide your email address or any other information about yourself. You only need to enter the above Meeting ID and you can join without any further ado. 

And at 1800Z/UT (until whenever we're tired) I will host another Q&A so please feel free to drop in and discuss whatever you like! 

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


On Sun, Aug 9, 2020 at 3:58 PM Gerald Ball via groups.io <gerryball2=talktalk.net@groups.io> wrote:
Thanks Hans
For a brilliant evening and superb tour of the Summers emporium and all the info that came across during the Q & A session. Sorry had to exit Zoom about 11pm. Unlike you youngsters I couldn't stay awake. will look for any recording.

Keep up the good work. Have just completed and boxed my 6th QCX  (all frequencies) And now waiting for the rest of the HF bands to improve. All working perfectly. Congratulations to you and your XYL on your anniversary, and well done handling the emergency and getting the children down to sleep. Remember it well.

73 Gerry G4OJF


Re: 0.03w RF output, 1w at transistor drains, Help? #qcx

ajparent1/KB1GMX
 

There is not 5.2W at the transistor gates ever!  Maybe 5.2V.

IF the power out is really low and the power at the drains blown devices
are often the first call.   However before going that far and a new build
soldering is usually the first and mostly likely suspect.

Hif you heard a snap look at the devices (bs170s finals) and
Q6 for visual clues.

Allison
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Re: Most accurate way to test rf output #qcx40

ajparent1/KB1GMX
 

I test for RF power using Bird wattmeter. Its good enough for most tasks (5% ful scale).
With a 5W  or 10W HF slug its going to be more accurate than needed as its easy to
see 2W vs 4.5.

IF I need more accurate I use calibrate power attenuator (Narda or Bird), additional
attenuators as needed (minicircuits and Kaye) and then into a Spectrum analyzer
(calibrated).  Often that is much more accurate than needed (sub .1db).

For checking a QCX for normal power verses not correct power a simple dummy
load with diode for peak voltage.  It will be more accurate than needed.
I have one of these built up for .1 to 10W use.  Accurate enough for casual
use (meter movement use limits it to about 5%).

A scope can be used instead of the diode detector IF the O'scope has
adequate bandwidth and has something approaching reliable calibration.

Which one is most accurate?  The DC meter checked against any number of
know sources accurate to 3 digits or so.

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


Re: QSO Today Virtual Ham Radio Expo - 08/09 August

Hans Summers
 

Hello all

Thanks, it was nice to chat to so many of you yesterday! 

For those that could not attend - the shack tour was in fact recorded so I am going to see if I can get it on YouTube then people can watch it there. 

The expo chat room is open all day and so feel free to drop in there, it supports keyboard chat, voice chat and video chat. The ZOOM video conference is also open all day see http://qrp-labs.com/zoom

Meeting ID: 838 2352 7803
Passcode: 299230
Link to meeting: https://www.zoom.us/join

Note that you do NOT need a Zoom account to join the zoom meeting. You do not need to provide your email address or any other information about yourself. You only need to enter the above Meeting ID and you can join without any further ado. 

And at 1800Z/UT (until whenever we're tired) I will host another Q&A so please feel free to drop in and discuss whatever you like! 

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


On Sun, Aug 9, 2020 at 3:58 PM Gerald Ball via groups.io <gerryball2=talktalk.net@groups.io> wrote:
Thanks Hans
For a brilliant evening and superb tour of the Summers emporium and all the info that came across during the Q & A session. Sorry had to exit Zoom about 11pm. Unlike you youngsters I couldn't stay awake. will look for any recording.

Keep up the good work. Have just completed and boxed my 6th QCX  (all frequencies) And now waiting for the rest of the HF bands to improve. All working perfectly. Congratulations to you and your XYL on your anniversary, and well done handling the emergency and getting the children down to sleep. Remember it well.

73 Gerry G4OJF


Re: Most accurate way to test rf output #qcx40

Don, ND6T
 

My choice is a good oscilloscope. With a good dummy load I can always get better than 1% accuracy. The best of swr/wattmeters have about 5%, if that. As a reference I use an old HP bolometer. I cross check every type of test with other equipment but always go back to the oscilloscope as the best on my bench. And you are correct, the 'scope is just about indispensable when it comes to seeing what is going on within a circuit. An educational tool in itself. I recently sold my old Rigol DS1102e for $100 and bought a new DS1202Ze for $299. Very much worth it for me. It even decodes SPI and I2C serial bit streams. Still cheaper than a modest espresso machine (to put it in perspective). That's my 2 cents worth. -Don


Re: Ultimate U3S #u3s #filter #lpf

John McClun
 

Jules,

I'm at the same point.  Have 4 filters done, in Diagnostic Mode waiting for the last filters and attach antenna.  Maybe I'll hear yours and I hope mine gets out as far as you.  We'll see.

John
NA3NA


Re: Encoder type/mfgr. QCX?

jjpurdum
 

If you don't have a scope, ask your club members for help. Also, some high school physics labs, junior colleges or universities are usually more than willing to help.

Contact bounce can be bad enough to send a false pulse chain to the microcontroller. You can reduce the problem in software or hardware. I used to solder 0.01µF caps from pins A and B to GND and that usually took care of the problem. Lately, I've been more lazy and am doing a software debounce using a non-blocking delay. (The common delay() routine uses its own interrupt and can block any interrupt you might be using.) You can usually do a little trial-and-error to find the smallest delay that eats the false pulse chain.

Finally, some libraries (https://github.com/brianlow/Rotary) (I think??) have symbolic constants that can account for quarter, half, and full cycle differences. (I've slept since I last checked.) Anyway, with a little tinkering, you can probably get just about any encoder to do the job.

Jack, W8TEE





On Sunday, August 9, 2020, 7:15:36 AM EDT, Tom Puckett, W5JXM <thpuckett@...> wrote:


Two aspects of many rotary mechanical encoders that can bite you if you don’t allow for them in your code or circuitry:

1.  An internal switch arm will not always make a clean simple transition between states:  the arm will sometimes bounce enough upon contact closure to break the closure, and then close again, which results in multiple transitions in the voltage waveform.  I’ve seen as many as a dozen extra transitions of this sort.  The waveform processing code/circuitry needs to be smart enough to allow for this situation and pass only a single transition in its output.

2. The encoder may be built as what I will call a full-cycle or a half-cycle device.  In a half-cycle device one detent’s worth of shaft rotation will result in the switch arm(s) making a single transition: an open arm will close, and a closed arm will open.  In a full-cycle device this will be automatically followed by another internally generated half-cycle which returns the arm(s) to their original state.

No, you cannot depend upon the encoder manufacturer’s spec sheet to discuss any of the above.  However if you have access to a scope then a few minutes testing will show you what’s actually going on.

73
Tom/W5JXM


Re: QSO Today Virtual Ham Radio Expo - 08/09 August

Gerald Ball
 

Thanks Hans
For a brilliant evening and superb tour of the Summers emporium and all the info that came across during the Q & A session. Sorry had to exit Zoom about 11pm. Unlike you youngsters I couldn't stay awake. will look for any recording.

Keep up the good work. Have just completed and boxed my 6th QCX  (all frequencies) And now waiting for the rest of the HF bands to improve. All working perfectly. Congratulations to you and your XYL on your anniversary, and well done handling the emergency and getting the children down to sleep. Remember it well.

73 Gerry G4OJF


Re: Encoder type/mfgr. QCX?

Alan de G1FXB
 

On 09/08/2020 12:15, Tom Puckett, W5JXM wrote:
No, you cannot depend upon the encoder manufacturer’s spec sheet to discuss any of the above. However if you have access to a scope then a few minutes testing will show you what’s actually going on.

If you haven't got a scope you can connect LED's on the two internal switch lines and observe the how the switching phase progresses during rotation to draw a state table and compare it to the other encoder


Alan


Re: Encoder type/mfgr. QCX?

Tom Puckett, W5JXM
 

Two aspects of many rotary mechanical encoders that can bite you if you don’t allow for them in your code or circuitry:

1. An internal switch arm will not always make a clean simple transition between states: the arm will sometimes bounce enough upon contact closure to break the closure, and then close again, which results in multiple transitions in the voltage waveform. I’ve seen as many as a dozen extra transitions of this sort. The waveform processing code/circuitry needs to be smart enough to allow for this situation and pass only a single transition in its output.

2. The encoder may be built as what I will call a full-cycle or a half-cycle device. In a half-cycle device one detent’s worth of shaft rotation will result in the switch arm(s) making a single transition: an open arm will close, and a closed arm will open. In a full-cycle device this will be automatically followed by another internally generated half-cycle which returns the arm(s) to their original state.

No, you cannot depend upon the encoder manufacturer’s spec sheet to discuss any of the above. However if you have access to a scope then a few minutes testing will show you what’s actually going on.

73
Tom/W5JXM