Date   
Re: Antuino - the antenna analyzer

K5ESS
 

Jerry,

Despite the data sheet implying that pins 1,4,and 5 are tied together internally only pins 1 and 5 are tied together.  I just examined one to confirm this.

Mike

K5ESS

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Jerry Gaffke via Groups.Io
Sent: Thursday, December 27, 2018 11:55 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Antuino - the antenna analyzer

 

My ADE-1 document just says that pins 1,4,5 are all ground, 
3 is RF, 6 is LO, and 2 is IF. out.
Your schematic suggests that 4 is only the "ground" for the RF port,
and is not connected to the other two ground pins internally.

I suppose R21,R29,R16, and an antenna on P3 would form a balanced
bridge when the antenna is 50 ohms, CLK1 is driving the antenna and the top of the bridge.
The ADE-1 RF port sees any imbalance across the bridge.
CLK2 into the LO port is 25mhz above (or below) CLK1.

Still no idea what CLK0 and P4 are up to.

Jerry

On Thu, Dec 27, 2018 at 09:35 PM, Jerry Gaffke wrote:

And last but not lest, what the devil is going on around that ADE-1 mixer?

Re: Bitx40 - Not Transmitting #bitx40help #bitx40

Gary.ingle@...
 

Hooray  !!!  Thank you all for the assistance.

The root cause was connecting the mic with the wrong polarity.

A new mic and correct polarity connection and I am sorted.

I have learned a valuable lesson, thank you all

Gary

Re: Bitx40 - Not Transmitting #bitx40help #bitx40

Timothy Fidler
 

Which is to say the old mike failed then you put a new one in with wrong polarity ? 
 

Timothy E. Fidler : Engineer BE Mech(1) Auckland , NDT specialist AINDT UT /RT3 , MT2 CB #2885, 
Telephone Whangarei   022  691 8405
e: Engstr@...



----- Original Message -----
From:
BITX20@groups.io

To:
<BITX20@groups.io>
Cc:

Sent:
Fri, 28 Dec 2018 09:41:53 -0800
Subject:
Re: [BITX20] Bitx40 - Not Transmitting #bitx40help #bitx40


Hooray  !!!  Thank you all for the assistance.

The root cause was connecting the mic with the wrong polarity.

A new mic and correct polarity connection and I am sorted.

I have learned a valuable lesson, thank you all

Gary

Re: Straight Key Night

Scott McDonald
 

Any thoughts about a uBITX cw freq? 077 would seem a bad bet but it would be nice if we had a cw watering hole in addition to 177/277.

Hope to catch some of you on.  Scott Ka9p


On Dec 28, 2018, at 8:24 AM, Michael Walker <va3mw@...> wrote:

As a thought, if you own one of these you should get on the air on Monday night with your Ubitx for Straight Key Night.  It is a long old ham radio tradition.

Objective: This 24-hour event is not a contest; rather it is a day dedicated to celebrating our CW heritage. Participants are encouraged to get on the air and simply make enjoyable, conversational CW QSOs. The use of straight keys or bugs to send CW is preferred. There are no points scored and all who participate are winners.

Mike va3mw

Re: Antuino - the antenna analyzer

Arv Evans
 

Farhan

Very good RF analyzer design and build.  Is that going to become a BITX-Labs product
at some future time? 

Happy New Year!

Arv  K7HKL
_._


On Thu, Dec 27, 2018 at 9:28 PM Ashhar Farhan <farhanbox@...> wrote:
peeps,

while trying to measure the swr on the cubesats, i figured i couldnt use any of the analyzers i had access to. they were simply too big to be stuffed inside a 10 cm cube. my simple resistive bridge was too insensitive for any reasonable work. so, i sat down and made an antenna analyzer from a spare raduino. 

the code is wobbly and just about enough to get my work done. it works on a superhet principle. this is not my clever idea, rahul had mentioned this approach taken by a russian builder. i havent seen the original design. it would be interesting if rahul or someone can point me in the right direction.

the code and a pdf of the circuit is on https://github.com/afarhan/antuino. i am attaching the circuit for the lazy bones.

have a great holiday and get some dx !!

- f

Re: Antuino - the antenna analyzer

MadRadioModder
 

This could easily be turned into a simple SA.  I’ll bet Kees already has the boards mocked up…

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Ashhar Farhan
Sent: Thursday, December 27, 2018 10:28 PM
To: bitx20@groups.io
Subject: [BITX20] Antuino - the antenna analyzer

 

peeps,

 

while trying to measure the swr on the cubesats, i figured i couldnt use any of the analyzers i had access to. they were simply too big to be stuffed inside a 10 cm cube. my simple resistive bridge was too insensitive for any reasonable work. so, i sat down and made an antenna analyzer from a spare raduino. 

 

the code is wobbly and just about enough to get my work done. it works on a superhet principle. this is not my clever idea, rahul had mentioned this approach taken by a russian builder. i havent seen the original design. it would be interesting if rahul or someone can point me in the right direction.

 

the code and a pdf of the circuit is on https://github.com/afarhan/antuino. i am attaching the circuit for the lazy bones.

 

have a great holiday and get some dx !!

 

- f


Virus-free. www.avg.com

--

…_. _._

Re: The K5BCQ AGC and PopFix schematics as pdf's, list of parts from Mouser

Jerry Gaffke
 

That list of part numbers is all surface mount, appropriate for 
the board design that Kees did.
My way of encouraging somebody else to take up producing the kits.

Here's the two threads relating to those kits.
    https://groups.io/g/BITX20/topic/18098324
    https://groups.io/g/BITX20/topic/22435274
Don, ND6T, came up with the circuit designs and built his by hand.
Kees, K5BCQ, did a board design, fabbed it, bought parts on reels,
and sent out nearly 1000 kits of each.

For a one-off, could fab the board using those gerbers from Kees.
But I'd probably just solder parts ugly style to a scrap of PC board,
or perhaps directly to the ground plane on the back of the Bitx40 or uBitx, 

All those parts are available in a through-hole version, if that's what you want.
The surface mount parts that Kees used are extremely small.
Could move up from 0805 to 1206 surface mount resistors and caps if not using Kees' gerbers.

Resistors and caps don't need special parts, 20% tolerance is fine.
I'd go for caps rated for 25 volts or more, though less should be sufficient.

Jerry, KE7ER



On Thu, Dec 27, 2018 at 08:56 PM, Jerry Gaffke wrote:
Here's a list of parts, quantities are for both boards together, looks good but not verified:
Prices are around a $0.10 each for semiconductors, $0.05 for caps and resistors,  if buying 10 at a time.
Columns are:  quantity,  generic part number,  package,  Mouser part number.

2  1N4148W    SOD-123    78-1N4148W-E3-18
1  MMBT3904   SOT-23    771-MMBT3904T/R
5  2N7002   SOT-23         757-T2N7002AKLM
5  10nF        0805             710-885012207092
2  100nF      0805             710-885012207098
4  1uF        0805               710-885012207078
1  1k           0805               755-ESR10EZPJ102
2  10k         0805               755-ESR10EZPJ103
7  100k       0805               755-ESR10EZPJ104
3  330k       0805               755-ESR10EZPJ334
1  1meg      0805               755-ESR10EZPJ105

Re: Antuino - the antenna analyzer

Jerry Gaffke
 

It already is a simple SA.
Just shut down CLK1 coming out of the SI5351.
Includes a tracking generator at CLK0/P4.

Jerry, KE7ER


On Fri, Dec 28, 2018 at 10:41 AM, MadRadioModder wrote:
This could easily be turned into a simple SA. 

Re: BitX40 low power output #bitx40

Jerry Gaffke
 

The audio chain is just the mike pre-amp at Q12.
A good start would be to check for the DC voltages that Randy gave us.
Key the mike, but no need for audio into the mike.

Next step is to do Allard's mods (either version), and see if you get full power as a CW transmitter.

If it works for CW, then (on the Bitx40) it all comes back to trouble around the mike and Q12.
If you can figure out a way to feed 50mv of 1khz audio into the mike amp, maybe try that.
But mostly just inspect those parts for bad solder joins, bad wiring to the mike, bad mike,
perhaps probe around as much as you can with an ohmmeter to verify that things are still soldered together ok.

Jerry, KE7E



On Fri, Dec 28, 2018 at 07:07 AM, David Arthur wrote:
Jerry, thanks for the tips. I was able to adjust RV1 and see 100mA with the key down and no audio input. However, I do not see the 1A current when shouting/whistling into the mic. My "power meter" is a QRP Labs dummy load with pinouts for the voltage across the resistors (and a formula for calculating watts). I still only see 3V peak across the load which is very low (should be like 20V or more I think).

How can I further inspect the audio chain to see where my signal is dropping off?

Re: uBITXv4 for sale #ubitx

 

The radio has been SOLD!
Thanks,
Jim

Re: uBITXv4 for sale #ubitx

Bob Lunsford <nocrud222@...>
 

RE:
This is too many radios...

Inline image

Jack W8TEE

Now, that is worthy of a feature article in QST. I have to wonder
how you find the time to spread around the operating table/s for
keeping those radios in shape...

The Radio Museum in Huntington, WV would love to have a pic
of your station to post on one of their walls.

Bob — KK5R

--------------------------------------------

On Fri, 12/28/18, Jack Purdum via Groups.Io <jjpurdum=yahoo.com@groups.io> wrote:

Subject: Re: [BITX20] uBITXv4 for sale #ubitx
To: BITX20@groups.io
Date: Friday, December 28, 2018, 9:57 AM



I have too many radios!

Naw. This is too many
radios...


Jack W8TEE







On Friday, December 28, 2018, 8:46:12 AM
EST, Jim Reagan <@jrprogrammer> wrote:





I have too many
radios! (like 6 transceivers, including another uBITX) 
This is a version 4 uBITX in a nice case (Fry's).  It
has a 2.8" Nextion display, AGC/S meter, Axicom relays,
and an LM386 audio amp. (The original audio is all there,
just not loud enough for me) Includes power cord and mike. I
used it on FT8 and SSB.  Asking $199, which includes USPS
Priority shipping CONUS only.  Thanks, Jim W0CHL

Re: uBITXv4 for sale #ubitx

Mike Short
 

I ship all over the world and have not had any issues 

On Fri, Dec 28, 2018 at 7:08 PM Bob Lunsford via Groups.Io <nocrud222=yahoo.com@groups.io> wrote:
RE:
This is too many radios...

Inline image

Jack W8TEE

Now, that is worthy of a feature article in QST. I have to wonder
how you find the time to spread around the operating table/s for
keeping those radios in shape...

The Radio Museum in Huntington, WV would love to have a pic
of your station to post on one of their walls.

Bob — KK5R

--------------------------------------------
On Fri, 12/28/18, Jack Purdum via Groups.Io <jjpurdum=yahoo.com@groups.io> wrote:

 Subject: Re: [BITX20] uBITXv4 for sale #ubitx
 To: BITX20@groups.io
 Date: Friday, December 28, 2018, 9:57 AM



                 I have too many radios!

 Naw. This is too many
 radios...


 Jack W8TEE







                     On Friday, December 28, 2018, 8:46:12 AM
 EST, Jim Reagan <jimreagans@...> wrote:





                 I have too many
 radios! (like 6 transceivers, including another uBITX) 
 This is a version 4 uBITX in a nice case (Fry's).  It
 has a 2.8" Nextion display, AGC/S meter, Axicom relays,
 and an LM386 audio amp. (The original audio is all there,
 just not loud enough for me) Includes power cord and mike. I
 used it on FT8 and SSB.  Asking $199, which includes USPS
 Priority shipping CONUS only.  Thanks, Jim W0CHL










Re: uBITXv4 for sale #ubitx

Jerry Gaffke
 

But wait...  There's more!
    https://www.qrz.com/db/W9EVT

He's an equal opportunity collector.
I saw my long lost piece-o-crap Hallicrafters S120 in there,
about 10 down from Jack's photo, top left.
Also the ARC-5 receiver I used while in college.

Look hard enough at those photos and you will find every piece
of store-bought communications gear you ever touched.

Jerry


On Fri, Dec 28, 2018 at 06:57 AM, Jack Purdum wrote:
Naw. This is too many radios...

Re: uBITXv4 for sale #ubitx

Jack, W8TEE
 

Bob:

That's not my shack. It belongs to George Ulm, W9EVT. Everyone I show the picture to says it's a remarkable collection. No, what's remarkable is his wife and that he's still married!

Jack, W8TEE

On Friday, December 28, 2018, 7:08:03 PM EST, Bob Lunsford via Groups.Io <nocrud222@...> wrote:


RE:
This is too many radios...

Inline image

Jack W8TEE

Now, that is worthy of a feature article in QST. I have to wonder
how you find the time to spread around the operating table/s for
keeping those radios in shape...

The Radio Museum in Huntington, WV would love to have a pic
of your station to post on one of their walls.

Bob — KK5R

--------------------------------------------
On Fri, 12/28/18, Jack Purdum via Groups.Io <jjpurdum=yahoo.com@groups.io> wrote:

Subject: Re: [BITX20] uBITXv4 for sale #ubitx
Date: Friday, December 28, 2018, 9:57 AM


       
                I have too many radios!

Naw. This is too many
radios...


Jack W8TEE


       
       
           
               
               
                    On Friday, December 28, 2018, 8:46:12 AM
EST, Jim Reagan <jimreagans@...> wrote:
               
               

               

                I have too many
radios! (like 6 transceivers, including another uBITX) 
This is a version 4 uBITX in a nice case (Fry's).  It
has a 2.8" Nextion display, AGC/S meter, Axicom relays,
and an LM386 audio amp. (The original audio is all there,
just not loud enough for me) Includes power cord and mike. I
used it on FT8 and SSB.  Asking $199, which includes USPS
Priority shipping CONUS only.  Thanks, Jim W0CHL



           
       




Re: Antuino - the antenna analyzer

Ashhar Farhan
 

the challenge would be to eliminate the if image. this could be done when you sweep to both sides and eliminate the image reading in software. here is an example :

1. lets imagine that there is a signal at 10 mhz. for this, we set the local oscillator at 35 mhz (as the IF is at 25 mhz). how can we be certain that the signal we are resolving is not at 60mhz (60mhz - 35 mhz = 25 mhz)?
2. we can take a second reading by setting the local oscillator at 85 mhz. in this csse, thr 60 mhz response (if any) should show up. else we can confirm that the signal we resolved in step 1 is indeed a 10 mhz signal.

one has to be aware that such a system will be slow. lets imagine that you have to sweep 30 mhz. the crystal filter is 10 khz wide. hence, we will need 30,000/5 = 6000 readings. if we can get, 100 readings a second, this will take a minute to complete the scan. an alternative would be to have two filters, a crystal filter and a 4 or even 5 section LC filter at around 12 mhz. we could switch to the lc filter for large sweeps. my specan circuit has a suitable design.

you are aking what happens if there was signal at 110 mhz in step two? aaaah, you tell me!

- f

On Sat, 29 Dec 2018, 00:48 Jerry Gaffke via Groups.Io <jgaffke=yahoo.com@groups.io wrote:
It already is a simple SA.
Just shut down CLK1 coming out of the SI5351.
Includes a tracking generator at CLK0/P4.

Jerry, KE7ER

On Fri, Dec 28, 2018 at 10:41 AM, MadRadioModder wrote:
This could easily be turned into a simple SA. 

Re: uBITXv4 for sale #ubitx

K5ESS
 

I apologize if this is a bit morbid, but the mother of all estate sales on Ebay looms in the future.

Mike

K5ESS

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Jerry Gaffke via Groups.Io
Sent: Friday, December 28, 2018 9:22 PM
To: BITX20@groups.io
Subject: Re: [BITX20] uBITXv4 for sale #ubitx

 

But wait...  There's more!
    https://www.qrz.com/db/W9EVT

He's an equal opportunity collector.
I saw my long lost piece-o-crap Hallicrafters S120 in there,
about 10 down from Jack's photo, top left.
Also the ARC-5 receiver I used while in college.

Look hard enough at those photos and you will find every piece
of store-bought communications gear you ever touched.

Jerry


On Fri, Dec 28, 2018 at 06:57 AM, Jack Purdum wrote:

Naw. This is too many radios...

Re: uBITXv4 for sale #ubitx

Bob Lunsford <nocrud222@...>
 

And if it were to become by possibly various way a radio museum
or the items were to be a radio museum?

I wonder too if there is not someone who would want to be the
owner of such a collection in its entirety and had the wherewithal
to make it happen. It seems somehow undesirable that there
would be a break-up of such a collection. In many ways, it IS
amateur radio history.

My imagination working here and I do not mean to be morbid about it.

Bob — KK5R

--------------------------------------------

On Fri, 12/28/18, K5ESS <k5ess.nothdurft@...> wrote:

I apologize if this is a bit morbid, but the mother of all estate sales on Ebay looms in the future.

Mike

K5ESS



From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Jerry Gaffke via Groups.Io
Sent: Friday, December 28, 2018 9:22 PM
To: BITX20@groups.io
Subject: Re: [BITX20] uBITXv4 for sale #ubitx



But wait... There's more!
https://www.qrz.com/db/W9EVT

He's an equal opportunity collector.
I saw my long lost piece-o-crap Hallicrafters S120 in there,
about 10 down from Jack's photo, top left.
Also the ARC-5 receiver I used while in college.

Look hard enough at those photos and you will find every piece
of store-bought communications gear you ever touched.

Jerry

Re: Antuino - the antenna analyzer

Jerry Gaffke
 

I was assuming the Antuino would have a set of front end filters for each region of interest.
Though the 25mhz IF is kind of low for this to be convenient.

Arv's DC receiver as a spectrum analyzer is also worth considering. 

I've had parts here for a year or so to build a 0-55mhz spectrum analyzer 
around two of the PX1002 86.85mhz SAW filters.  
Seeing the Antuino, I'm inspired enough to have parts splayed out on my workbench,
an enclosure selected, am about to cut the bare PC board to fit. 
Will build ugly style, use 3/4" copper pipe cut into 1/4" high cylinders
to provide a shield for each section, bolt a plate over the top once it works.
Signals going off to the next shielded section will have a wire through a hole
in the board to to where it's held down to the back groundplane using copper tape. 
So almost coax, the one inch runs short enough that impedance won't be an issue.
But by selecting appropriate wire diameter and insulation thickness, might hit 50 ohms.

And if it works, maybe add another stage up front using a 915mhz SAW filter.
That first VFO would have to do something like 915 to 1500mhz.
Either a clock doubler on the 1000mhz si5340, or perhaps the si549.
But of course, I'll have a hard time looking at that stuff when it doesn't work.

Anybody have a feel for how well the cheap $200 laptop based spectrum analyzers
are doing?  Is there much reason to homebrew other than as a hobby?
How do those $200 units compare to a Rigol SA?

Jerry, KE7ER


On Fri, Dec 28, 2018 at 08:05 PM, Ashhar Farhan wrote:
the challenge would be to eliminate the if image. this could be done when you sweep to both sides and eliminate the image reading in software. here is an example :
 
1. lets imagine that there is a signal at 10 mhz. for this, we set the local oscillator at 35 mhz (as the IF is at 25 mhz). how can we be certain that the signal we are resolving is not at 60mhz (60mhz - 35 mhz = 25 mhz)?
2. we can take a second reading by setting the local oscillator at 85 mhz. in this csse, thr 60 mhz response (if any) should show up. else we can confirm that the signal we resolved in step 1 is indeed a 10 mhz signal.
 
one has to be aware that such a system will be slow. lets imagine that you have to sweep 30 mhz. the crystal filter is 10 khz wide. hence, we will need 30,000/5 = 6000 readings. if we can get, 100 readings a second, this will take a minute to complete the scan. an alternative would be to have two filters, a crystal filter and a 4 or even 5 section LC filter at around 12 mhz. we could switch to the lc filter for large sweeps. my specan circuit has a suitable design.
 
you are aking what happens if there was signal at 110 mhz in step two? aaaah, you tell me!
 
- f

Re: Antuino - the antenna analyzer

Ashhar Farhan
 

jerry, 
we need 80 db dynamic range for useful work with specans. at 6db per bit, this pushes for a 14 bit dac or better. these, including thr rtl-sdr family are hardly useful.
for a radio amateur, a double conversion specan can easily be buily for less than $100 providing as good a performance as thr professional ones with limited range and bandwidth selection.
with 110 mhz as the first IF and 12 mhz as the second, onr can span 0-70 mhz easily 
- f

On Sat, 29 Dec 2018, 11:16 Jerry Gaffke via Groups.Io <jgaffke=yahoo.com@groups.io wrote:
I was assuming the Antuino would have a set of front end filters for each region of interest.
Though the 25mhz IF is kind of low for this to be convenient.

Arv's DC receiver as a spectrum analyzer is also worth considering. 

I've had parts here for a year or so to build a 0-55mhz spectrum analyzer 
around two of the PX1002 86.85mhz SAW filters.  
Seeing the Antuino, I'm inspired enough to have parts splayed out on my workbench,
an enclosure selected, am about to cut the bare PC board to fit. 
Will build ugly style, use 3/4" copper pipe cut into 1/4" high cylinders
to provide a shield for each section, bolt a plate over the top once it works.
Signals going off to the next shielded section will have a wire through a hole
in the board to to where it's held down to the back groundplane using copper tape. 
So almost coax, the one inch runs short enough that impedance won't be an issue.
But by selecting appropriate wire diameter and insulation thickness, might hit 50 ohms.

And if it works, maybe add another stage up front using a 915mhz SAW filter.
That first VFO would have to do something like 915 to 1500mhz.
Either a clock doubler on the 1000mhz si5340, or perhaps the si549.
But of course, I'll have a hard time looking at that stuff when it doesn't work.

Anybody have a feel for how well the cheap $200 laptop based spectrum analyzers
are doing?  Is there much reason to homebrew other than as a hobby?
How do those $200 units compare to a Rigol SA?

Jerry, KE7ER


On Fri, Dec 28, 2018 at 08:05 PM, Ashhar Farhan wrote:
the challenge would be to eliminate the if image. this could be done when you sweep to both sides and eliminate the image reading in software. here is an example :
 
1. lets imagine that there is a signal at 10 mhz. for this, we set the local oscillator at 35 mhz (as the IF is at 25 mhz). how can we be certain that the signal we are resolving is not at 60mhz (60mhz - 35 mhz = 25 mhz)?
2. we can take a second reading by setting the local oscillator at 85 mhz. in this csse, thr 60 mhz response (if any) should show up. else we can confirm that the signal we resolved in step 1 is indeed a 10 mhz signal.
 
one has to be aware that such a system will be slow. lets imagine that you have to sweep 30 mhz. the crystal filter is 10 khz wide. hence, we will need 30,000/5 = 6000 readings. if we can get, 100 readings a second, this will take a minute to complete the scan. an alternative would be to have two filters, a crystal filter and a 4 or even 5 section LC filter at around 12 mhz. we could switch to the lc filter for large sweeps. my specan circuit has a suitable design.
 
you are aking what happens if there was signal at 110 mhz in step two? aaaah, you tell me!
 
- f

Re: Antuino - the antenna analyzer

Jerry Gaffke
 

Tacking an AD8307 into a uBitx between the 12mhz crystal filter and the demodulator
could make it useful as a spectrum analyzer.  
Given the better crystal filter and the higher first IF of the uBitx,
should be a better choice than an Antuino.
Though may not fit into a cubesat.

The AD8307 is $13 each up on Mouser.
Ebay sellers have them at about $0.30 each.
The ebay parts reportedly work well enough, but may be a bit out of spec
with regard to calibration.
  
Jerry


On Fri, Dec 28, 2018 at 09:46 PM, Jerry Gaffke wrote:
I was assuming the Antuino would have a set of front end filters for each region of interest.
Though the 25mhz IF is kind of low for this to be convenient.