Date   
Re: Simple vfo sketch

Gordon Gibby <ggibby@...>
 

Make a simple common emitter  amplifier like one of those in the bitx.  Maybe a gain of six or eight or so.   


On Jan 14, 2019, at 21:16, James Lynes <jmlynesjr@...> wrote:

Don:

I have a version of Allard's v1.26 configured as a VFO for my ZZRX40 DC receiver. Which by the way I've now logged all 50 states with. It currently tunes 7.000 to 7.300, but it's easy to change.

I stripped out all the code I don't need.

Send me your email if interested. You'll need the IDE to compile/load it.

James
KE4MIQ

Re: Tracing receive signal for low signal

Dave Space
 

Hmm seems like the transmit is ok.  Maybe adjusting the BFO before solved that issue too... all seems ok there.

Might have to look into a good push to talk mic replacement but other than that sounds ok.

So my list of items now is probably something like
New Mic
Check for transmit spurs
(Fix the inevitable transmit spurs?)
AGC or
Thinking about JackAl board it's got some nice features though (think it even has AGC on it).  (Though costs almost as much as another ubitx board with all the extra boards you need to buy)

Re: Blown finals?

Ripley
 

I can only speak to my uBITX in particular but spurs where a problem running the radio on 12 volts. Using the the 45 MHz crystal mod in place of R27 brought them down to FCC compliance except for the pesky 12 MHz spur on 10 meters. I am going to try Raj’s modification replacing L5 and L7 with surface mount inductors.

 

Ripley

 

Sent from Mail for Windows 10

 

From: Bob Lunsford via Groups.Io
Sent: Monday, January 14, 2019 8:39 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Blown finals?

 

A converted computer power supply to become a general

power supply usually turns them into a 12.X V. power supply.

This would be a good way to go. However...

 

If I want to run the radio in the car as a mobile on 40M, the

car's supply is about 13.6V so I would still need to drop the

supply to 12V. However, I think I remember that the RF Amp

can be run at a higher voltage so the original plan may still

be appropriate: Run the radio on 12V and the Amp on 13.8V.

 

Just making plans here as I go. Running the radio on 1A

diodes is not a problem but a beefier diode may be in order

for the MRF diodes since they run more current. 12V for

the radio and 13.6V for the RF Amp.

 

I also wonder if the spurs, etc., would be less of a problem if

the radio is run at 12V instead of 13.8V...?

 

Bob — KK5R

 

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

On Mon, 1/14/19, Ripley <bob.ripley@...> wrote:

 

Subject: Re: [BITX20] Blown finals?

To: "BITX20@groups.io" <BITX20@groups.io>

Date: Monday, January 14, 2019, 8:28 PM

 #yiv2735320529

#yiv2735320529 --

 

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#yiv2735320529 I run mine at 12 volts. The

finals and everything else. No issues whatsoever.  Ripley  Sent from Mail

for Windows 10

 From: Bob

Lunsford via Groups.Io

Sent:

Monday, January 14, 2019 7:12 PM

To:

BITX20@groups.io

Subject: Re: [BITX20] Blown

finals?  I get the impression that the

uBitx is designed to operatedon 8V and the finals on

13.8V. Therefore, I plan to do this:  I will run the radio, etc.,

at 8V and the final amp at 13.8V.This means I will put eight

1A diodes in series with the13.8V and drop the voltage

down to near 9V. This shouldeliminate the problem with

the audio amp blowing becauseof too much heat due to a

higher voltage than needed.  This would run the main

board, etc. The amp would runat 13.6V which should not be

a problem.  Or, would it be better to run

the radio at 12V and the ampat 13.8V? Then I'd only

need three diodes.

 Bob — KK5R    --------------------------------------------On Mon, 1/14/19, Peter

Russell <peter.russell@...> wrote:   Subject: [BITX20] Blown

finals? To:

BITX20@groups.io Date:

Monday, January 14, 2019, 4:46 PM  It's now about a month

since I got my ubitx

and I haven't tried to  transmit as my power supply

wasn't up to

it. So I built a new

(5A) one. Powered with

the new PSU, I wound the bias controls fully

clockwise and  with

my meter checking the current, pressed the key. Turning RV2

 produced the

expected current increase, but turning RV3, no increase

at all! Must have

somehow blown one of the finals! So I ordered 3 new

IRF510's. I

changed the one I thought was at fault and tried again. Same problem. Must have changed the wrong

one! Changed the other

one. Same

problem. After a good

deal of bad language I got round to checking voltages

and  resistances

around the final circuits, where I realised that one of

the  bias circuits

was behaving very

strangely. To cut a

long story short, I removed RV3 from the board only to

find  that it had

broken one of its legs and was hanging only on two (

the  ground one had

snapped off!). So

I've ordered some presets. Maybe it's all those

tales of woe about

IRF510's that I've read on this  forum that made me think

that one had blown, or

maybe I should have done  what I was taught and

followed correct fault

finding procedure before  jumping in with both

feet. The presets

should be here tomorrow so I'll do a proper repair

job and  hopefully

learn a useful lesson.

DON'T TAKE TOO MUCH NOTICE OF FORUMS!  Peter G8FWY  --- This email has been checked

for viruses by

AVG.

https://www.avg.com

          

 

 

 

Re: JackAl Voltage Chart

Jim Sheldon
 

Has anyone been able to download the JackAl software from hamradiodesigns.com yet?  I thought it was supposed to be available today but the download on the website is still password protected.  Tried clearing the browser cache in case that was the problem but so far no luck.

W0EB

Re: JackAl Voltage Chart

Konrad Kristensen
 

Yes, but it was not straight forward. 

KA1LD/Konrad


On Jan 14, 2019, at 10:10 PM, Jim Sheldon <w0eb@...> wrote:

Has anyone been able to download the JackAl software from hamradiodesigns.com yet?  I thought it was supposed to be available today but the download on the website is still password protected.  Tried clearing the browser cache in case that was the problem but so far no luck.

W0EB

Re: JackAl Voltage Chart

Jack, W8TEE
 

All:

It is true, I wanted to release the software today, which was in line with QRP Guys distribution of the boards. Jim has written to me several times about the software not being distributed yet, and I did tell him I would release it today. Alas, there are still two parts that I'm not happy with so I did not release it today. Jim evidently thinks that bringing this to your attention will make me look bad and make his competing product (his board is for the Nextion display) look better, and perhaps it does. All I can say is that Al has done a fantastic job with the hardware and I'm working hard to match his craftsmanship, but on the software side.

There are several people who do have the software right now. They are our Beta testers, and Konrad is one of them. He has been especially helpful because he lives here in the city. For all of you who have already purchased the JackAl system, I will be releasing the software as soon as I can. When it is ready for prime time, I will post a notice here. In the meantime, bear with me for a few more days.

Jack, W8TEE

On Monday, January 14, 2019, 10:20:00 PM EST, Konrad Kristensen <konrad.kristensen@...> wrote:


Yes, but it was not straight forward. 

KA1LD/Konrad


On Jan 14, 2019, at 10:10 PM, Jim Sheldon <w0eb@...> wrote:

Has anyone been able to download the JackAl software from hamradiodesigns.com yet?  I thought it was supposed to be available today but the download on the website is still password protected.  Tried clearing the browser cache in case that was the problem but so far no luck.

W0EB

Re: Tracing receive signal for low signal

Dave Space
 

Might have got my answer to the spurs question transmitting on 7.150MHZ has -30 spurs about 750khz up and down and some -40 spurs all around there (and a bunch of smaller ones up and down that range).   There are -40 spurs on 14mhz and 21MHZ has a full on equivalent harmonic signal equal to the main transmit power there .

Any favorite spur fixes you recommend?

Fw: [BITX20] JackAl Voltage Chart

Jack, W8TEE
 

All:

Jim wrote to me stating that his product does not use the Nextion display and never has. You can see his product at Triumvirate Skonk Worx Website Page-Two


and view ours at:


He maintains that our products don't compete while I thought they did. Perhaps he's right. If I caused confusion about this, I apologize.

That said, I still cannot release the software at this moment. While the software has been working since we demo'ed it at FDIM just before last year's Dayton Hamvention, we have continued to improve and add to it and, rather than remove the last two features, I'd rather keep them in and have the software be a little late than throw them away.

I will release the software as soon as I can.

Jack, W8TEE

On Monday, January 14, 2019, 10:43:42 PM EST, Jack Purdum <jjpurdum@...> wrote:


All:

It is true, I wanted to release the software today, which was in line with QRP Guys distribution of the boards. Jim has written to me several times about the software not being distributed yet, and I did tell him I would release it today. Alas, there are still two parts that I'm not happy with so I did not release it today. Jim evidently thinks that bringing this to your attention will make me look bad and make his competing product (his board is for the Nextion display) look better, and perhaps it does. All I can say is that Al has done a fantastic job with the hardware and I'm working hard to match his craftsmanship, but on the software side.

There are several people who do have the software right now. They are our Beta testers, and Konrad is one of them. He has been especially helpful because he lives here in the city. For all of you who have already purchased the JackAl system, I will be releasing the software as soon as I can. When it is ready for prime time, I will post a notice here. In the meantime, bear with me for a few more days.

Jack, W8TEE

On Monday, January 14, 2019, 10:20:00 PM EST, Konrad Kristensen <konrad.kristensen@...> wrote:


Yes, but it was not straight forward. 

KA1LD/Konrad


On Jan 14, 2019, at 10:10 PM, Jim Sheldon <w0eb@...> wrote:

Has anyone been able to download the JackAl software from hamradiodesigns.com yet?  I thought it was supposed to be available today but the download on the website is still password protected.  Tried clearing the browser cache in case that was the problem but so far no luck.

W0EB

Re: Simple vfo sketch

MVS Sarma
 

Hi,
Farhan already published his antenna analyser (ANTUINO), where there is a free running osc on one of the clocks of his ANTUINO.
All the best
Sarma  vu3zmv

On Tue, 15 Jan 2019, 5:40 am Don Richards <ve3ids.don@... wrote:
I have built this version of the raduino, 


It works quite well with my HW 101 in receive. It needs a little more amplitude to drive the transmitter properly, that mod is in progress. 

My question to the group is, has anyone written a sketch for the raduino that is a simple RF generator that could be used as a signal generator or for a simple vfo for an old crystal transmitter, ie, one that simply generates the actual frequency that it displays on the LCD and still uses the tuning pot rather than an encoder?

I don't know nearly enough to create this, hoping that some of the talent that frequents this group has done this and can share. 

Thanks and 73
Don ve3ids

JackAl Voltage Chart

Christopher Miller
 

Why not remove them, release the source and then release a new version /after/ you fix the bugs?

If I recall correctly this person also attacked people from posting off topic on their thread promoting their product. Its a little disappointing in my humble opinion.

KF4FTR

Re: Tracing receive signal for low signal

jim
 

Just as a quick check ,,Do you have 2 seperate 12 v supplies? ...run all of microBitx EXCEPT finals on one supply, Just the finals (supplied on Brown 12 v wire) on the otherr supply ...check for spurs/cruft on output...

Jim

On Monday, January 14, 2019, 7:48:08 PM PST, Dave Space <davesspacebar@...> wrote:


Might have got my answer to the spurs question transmitting on 7.150MHZ has -30 spurs about 750khz up and down and some -40 spurs all around there (and a bunch of smaller ones up and down that range).   There are -40 spurs on 14mhz and 21MHZ has a full on equivalent harmonic signal equal to the main transmit power there .

Any favorite spur fixes you recommend?

Re: Blown finals?

 

I had reported this issue in the forum. The ppl at hfsignals twist the preset to fit the
heatsink and this sometimes breaks a lead.

You are lucky that it did not break the ground lead, this would have caused magic smoke.

Raj

At 15-01-19, you wrote:
It's now about a month since I got my ubitx and I haven't tried to transmit as my power supply wasn't up to it.
So I built a new (5A) one.
Powered with the new PSU, I wound the bias controls fully clockwise and with my meter checking the current, pressed the key. Turning RV2 produced the expected current increase, but turning RV3, no increase at all!
Must have somehow blown one of the finals!
So I ordered 3 new IRF510's.
I changed the one I thought was at fault and tried again.
Same problem.
Must have changed the wrong one!
Changed the other one.
Same problem.
After a good deal of bad language I got round to checking voltages and resistances around the final circuits, where I realised that one of the bias circuits was behaving very strangely.
To cut a long story short, I removed RV3 from the board only to find that it had broken one of its legs and was hanging only on two ( the ground one had snapped off!).
So I've ordered some presets.
Maybe it's all those tales of woe about IRF510's that I've read on this forum that made me think that one had blown, or maybe I should have done what I was taught and followed correct fault finding procedure before jumping in with both feet.
The presets should be here tomorrow so I'll do a proper repair job and hopefully learn a useful lesson.
DON'T TAKE TOO MUCH NOTICE OF FORUMS!

Peter G8FWY

Re: Tracing receive signal for low signal

Evan Hand
 

You can check via this thread here on Bitx20:
https://mail.google.com/mail/u/0/#label/Dev%2FUbitx/WhctKJVJcmQfRxkfBbkrTMhVPcbrFTKRHpddxvvsjsJkvQjrTHqWmGwdjHxzDFFRbLqkWmg

I would also do a search, as there are a number of threads on how to fix them.  I have not tried any, and there for can not say that one or the other has worked.

My plans were to 
1 - replace the relays
2 - install the shielded SMD coils for L5 and L7
3 - try to test for the spurs on 10m and 20m. If detected then go on to Ashhar's LPF fix of adding the LCL filter and resistor changes.

Now I am waiting to see the result of v5 testing, after the board is available.  From the post above, seems like there is more required for the low pass filter issues that will require an external board to overcome the layout issues.  So my plan now is wait and see.  I am also looking at signal analyzers, as what I currently have is fine for the harmonics tests, however it does not have good enough frequency discrimination to test for spurs

73
Evan
AC9TU

Re: Tracing receive signal for low signal

Dave Space
 

Only running one supply and it's basically just an old wall wart adapter that can run at 12v.  Supplies help a lot?  Have any suggestions on supplies?

Re: Tracing receive signal for low signal

Dave Space
 

Any idea when the v5 board is supposed to be out?

I was thinking about the relay replacements also - did you find a good source for them?
I'm just using an RTL-SDR to look at the frequencies I piped the ubitx output into the -40db attenuator into the rtl-sdr and looking at the output.

I have to look for the oscillator leaking/IMD that Ashar has fixes for also.

I was thinking about an idea to add more components offboard for the existing bandpass filters.

Is there a good way to track down the source of the spurs?  (I'm guessing some is based on understanding of the clocks/harmonics thus knowing the source based on frequency)

For example the huge 21mhz spur since it's 3rd harmonic of my transmit frequency source just seems likely vfo and either not enough bandpass filter attenuation, not working or leakage around the filter somehow?  (If it's leakage how best to track those things down, just probe around the transmit path and see where it shows up on the scope?

Thanks.



Re: JackAl Voltage Chart

Jack, W8TEE
 

Mornin' Christopher:

I hate releasing software with a known bug in it, even when it is one that doesn't really impact the functionality of the product. The bug is in the EEPROM that saves the setup information. An easy fix is to simply hard-code the values, but that requires programming which scares a lot of people. I know it's going to be a flat-forehead mistake on my part, so I'm fairly sure I'll get it fixed soon or have a viable work-around within a day or two.


Jack, W8TEE


On Tuesday, January 15, 2019, 1:06:17 AM EST, Christopher Miller <djmalak2k6@...> wrote:


Why not remove them, release the source and then release a new version /after/ you fix the bugs?

If I recall correctly this person also attacked people from posting off topic on their thread promoting their product. Its a little disappointing in my humble opinion.

KF4FTR

Apache cases on sale

Jack, W8TEE
 

All:

Harbor Freight has several different sizes of Apache cases on sale starting a $10. These cases have foam inserts that can be cut to suit and are almost watertight.

Jack, W8TEE

Re: Tracing receive signal for low signal

Evan Hand
 

I go the relays at Mouser:
https://www.mouser.com/ProductDetail/te-connectivity/v23105a5403a201/?qs=Nk6ydC%2fJI6we9mx5p4DWfg%3d%3d&countrycode=US&currencycode=USD

I believe you can do better on price if you go through ebay, though the lowest cost may take awhile in shipment.

I am not sure that I would trust my RTL-SDR to accurately measure for the harmonics/spurs.  I got different results when compared to my RF Explorer WSUB1G+, and the front end of the RTL-SDR seems to overload easily, giving strange results.  Again, I am not sure which one to believe.  They both do agree that there is a 3rd order harmonic at 21mhz that is higher than the -43db that is required in the US.

I would also read the following threads:
https://groups.io/g/BITX20/message/61256
https://groups.io/g/BITX20/topic/27001748#61457
https://groups.io/g/BITX20/topic/28049653#61551

There are more and the net of all of this is that there is not total agreement on the fixes that are required.

My interpretation is as follow (please understand that I am NOT and expert.  I have just read a LOT of the emails related to the uBitx)
1 - The relay replace is minimum and may not totally fix the harmonic issues.  The true fix is an external low pass filter board linked to the uBitx switching relays, or possible loss in receiver sensitivity if left in and manually switched when the band is changed.

2 - If you can fix the harmonics, then operation on bands 20m and lower in frequency  should not have the IMD issue.  You can reduce that with both Ashhar's and Raj's fixes combined.

3 - without the major modifications that are suggested by the v5 board changes, the v4 and earlier should NOT be used as the exciter to a PA, UNLESS you have the equipment and skill to verify the spurious radiation is under control.

I have been told in this group that in the "old days" spurious emissions where tested using another receiver located far enough away to not overload the front end.  In other words, have a friend that can hear your signal verify no spurious emissions.  This would involve scanning for them.  I am sure that was state of the art then, not sure the FCC would agree now.  We are responsible for our transmissions.

It has also been pointed out that with the normal power levels of the uBitx, that as long as you were close, the spurs would be so far down that it would not really cause interference or be noticed.  One of the reasons for me abandoning the PA until I know what to do to the uBitx.

As always, take my input with a grain of salt.
73
Evan
AC9TU

Re: Tracing receive signal for low signal

Jack, W8TEE
 

 Interesting. I checked the one-price for the relay at Digikey, Mouser, Arrow, and Newark and all but Arrow were the identical price, $2.81. Arrow is $2.67. I've been pleased with Arrow in terms of prices, service, and low shipping costs (sometimes, zero).

Jack, W8TEE

On Tuesday, January 15, 2019, 9:25:48 AM EST, Evan Hand <elhandjr@...> wrote:


I go the relays at Mouser:
https://www.mouser.com/ProductDetail/te-connectivity/v23105a5403a201/?qs=Nk6ydC%2fJI6we9mx5p4DWfg%3d%3d&countrycode=US&currencycode=USD

I believe you can do better on price if you go through ebay, though the lowest cost may take awhile in shipment.

I am not sure that I would trust my RTL-SDR to accurately measure for the harmonics/spurs.  I got different results when compared to my RF Explorer WSUB1G+, and the front end of the RTL-SDR seems to overload easily, giving strange results.  Again, I am not sure which one to believe.  They both do agree that there is a 3rd order harmonic at 21mhz that is higher than the -43db that is required in the US.

I would also read the following threads:
https://groups.io/g/BITX20/message/61256
https://groups.io/g/BITX20/topic/27001748#61457
https://groups.io/g/BITX20/topic/28049653#61551

There are more and the net of all of this is that there is not total agreement on the fixes that are required.

My interpretation is as follow (please understand that I am NOT and expert.  I have just read a LOT of the emails related to the uBitx)
1 - The relay replace is minimum and may not totally fix the harmonic issues.  The true fix is an external low pass filter board linked to the uBitx switching relays, or possible loss in receiver sensitivity if left in and manually switched when the band is changed.

2 - If you can fix the harmonics, then operation on bands 20m and lower in frequency  should not have the IMD issue.  You can reduce that with both Ashhar's and Raj's fixes combined.

3 - without the major modifications that are suggested by the v5 board changes, the v4 and earlier should NOT be used as the exciter to a PA, UNLESS you have the equipment and skill to verify the spurious radiation is under control.

I have been told in this group that in the "old days" spurious emissions where tested using another receiver located far enough away to not overload the front end.  In other words, have a friend that can hear your signal verify no spurious emissions.  This would involve scanning for them.  I am sure that was state of the art then, not sure the FCC would agree now.  We are responsible for our transmissions.

It has also been pointed out that with the normal power levels of the uBitx, that as long as you were close, the spurs would be so far down that it would not really cause interference or be noticed.  One of the reasons for me abandoning the PA until I know what to do to the uBitx.

As always, take my input with a grain of salt.
73
Evan
AC9TU

Re: low output only on 40m

Ted
 

Yes, I reported this symptom a week or two ago and was told something to the effect of, "wiggle the torroid chokes around a bit, they're not embedded in stone" or some such.  No resolution as of yet, and I'm working on a greater problem at present [ something stupid I did, while looking at the aforementioned as it haopens]  and I look forward to anything you hear about this where where to look. Good luck.

Ted
K3RTA