Date   

Re: Sideband Suppression (receive) #ubitx #ubitx-help

Arv Evans <arvid.evans@...>
 

Tim

Interesting.  How much carrier suppression do you get without tone insertion? 
Just terminate the mike input and balance the modulator without any modulation
being inserted.  If that dip is too shallow then it could point to the modulator diodes
themselves.

Arv
_._


On Sat, Apr 28, 2018 at 3:33 PM, Tim Gorman <tgorman2@...> wrote:
Arv,

I have a spectrum analyzer. I use a two-tone generator. There is no
issue with spurious microphone response. While the two-tone gen is
just a standard kit, I can't see any distortion on my oscilloscope in
either the time domain or in the frequency domain using the scopes
FFT math function. I'm sure there is some but not enough to cause
this carrier suppression figure. Nor are there any ultra-sonic tones
showing up on the spectrum scan, either at audio freq's or rf freqs.

Just a single tone from the two-tone generator and the carrier.

25db is the *best* I can get by adjusting the BFO. Standard adjustment
of the BFO gave about 18db to 22db. Moving the BFO down the filter
skirt gave me another 3db.

tim ab0wr

On Sat, 28 Apr 2018 11:13:53 -0600
"Arv Evans" <arvid.evans@...> wrote:

> Tim  AB0WR
>
> Some earlier BITX transceivers did use a ring mixer but the carrier
> suppression was
> not noticeably better than with the present design.  Allison's
> comments are valid and
> reflect a good place to start looking.
>
> Placing the BFO down the edge of the  crystal filter passband helps
> improve carrier
> rejection and improves audio by filtering off unneeded lower frequency
> voice products.
> You can tailor the lower frequency speech response by how far down the
> filter skirt
> you place the BFO.
>
> If you have means to do spectrum analysis you can measure crystal
> filter response
> and use that information to determine where the BFO should be set.
> If you do not
> have spectrum analysis tools, it is still possible to do a manual
> sweep by adjusting the
> BFO in small (20 to 100 Hz) steps across the filter passband and plot
> the filter output
> using a diode detector and graph paper.  Note that linear graph paper
> will show an
> expanded curve where log graph paper will show a more conventional
> decibel curve.
>
> If noise is being injected into the balanced modulator via the
> microphone or microphone
> amplifier it will not be possible to get a deep null in carrier
> balance. It is conventional
> practice to short the microphone input while doing carrier balance
> adjustments and
> measurement.
>
> Allison's comment regarding possibility of undetected ultra-sonic
> tones present that
> can cause unwanted carrier insertion is something that we do not
> usually look for.
> A quick look at modulator AF input with an oscilloscope would
> probably show any
> such problem.
>
> Typical crystal ladder filters usually show a steeper curve on its
> lower sideband than
> on the upper sideband.  Some of the high-IF designs ignore that and
> as a result will
> show less carrier rejection on either USB or LSB, depending on the
> design.
>
> https://goo.gl/ZGf8wR
>
> https://goo.gl/4Q8kCV
>
> http://www.qsl.net/g3oou/iffilters1.html
>
> <goog_592175929>
>
> http://tinyurl.com/y7re23nn
>
> Arv  K7HKL
> _._
>
>
>
> On Fri, Apr 27, 2018 at 8:50 PM, Tim Gorman <tgorman2@...> wrote:
>
> > I've never been able to get over 25db of carrier rejection
> > according to my Rigol DSA815. Not unless I move the BFO so far that
> > signals are unintelligible. If you adjust by 6db to allow for PEP
> > equivalence this is still only 31db of rejection.
> >
> > In looking at the modulator circuit I don't see much of a way to
> > increase carrier rejection without major butchery, i.e. totally
> > replacing the modulator with a ring mixer which would allow
> > providing for a carrier balance adjustment.
> >
> > tim ab0wr
> >
> > On Fri, 27 Apr 2018 18:22:21 -0700
> > "ajparent1/KB1GMX" <kb1gmx@...> wrote:
> > 
> > > Two things result in carrier...
> > >
> > > One is the BFO too close to or in the filter passband, it should
> > > be 6-10 db down the edge of the filter. Blaming the filter will
> > > not fix that, unless its seriously broken.    NOTE: Each unit
> > > will vary some on the best BFO setting this happens with
> > > commercial filters too.
> > >
> > > The other is imbalance in the modulator circuit.  Solution is fix
> > > it.
> > >
> > > There is a remote possibility of a tone at higher than you can
> > > here present in the tx due to a circuit or wiring issue.
> > >
> > > Its not rocket science to measure the power out and the residual
> > > carrier.  a 50 ohm load, a diode detector is all that is needed
> > > plus a voltmeter.  Compare power out at full power and with no
> > > audio at all the ratio in DB should be better than 40DB
> > > (10,000:1) or for 10W out less than 1mW.
> > >
> > > Allison 
> >
> >
> >
> >
> > 






Re: Please don't make Radiuno with CH340/CH341 chipsets any more! Or at least advertise that you do use them! #radiuno

Andrew Merrybard
 

Just as an aside. I am having good luck with he drivers for the CH340 (etc) from
mac-usb-serial.com
​.

I went through various patches of failures and crashed as the OS gets updated.
It is a real PIA to solve. I am hoping the mac-usb-serial.com driver is going
to solve this for me.

About 8 euros to buy I think.

They d
​e​
scribe the
​i​
r product as
​ ​
High-end macOS drivers for your PL-2303, CH341
and CP2102 USB to Serial devices
​.

7
​3​

Andrew​

VK6WAM

On 29 April 2018 at 04:49, Mike Woods <mhwoods@...> wrote:
On 29/04/18 8:34 AM, ab2ts wrote:
I plugged the Radiuno into my Mac and tried to program it with the Arduino GUI and let loose with a few expletives.  I knew immediately what had happened.   I usually do my homework and avoid the CH34x chipsets in my Arduino projects, but Radiuno was not offered in another form and I neglected to check the chipset.    (I still haven't found a spec for Radiuno that says what chipset it uses; clearly it is a CH340.)

 I solved the problem by digging out a very old MacBookPro with an antique OS which does did not have the security feature and did support CH34x chipsets.  While it is slow, it fortunately it runs the latest version of Arduino.   My other alternative would have been to remove the CHxx Arduino Nano and replace it with an FTDI or Prolific PL2303 Arduino Nano...   I may do that yet am not looking forward to it.  

This may be a solution:

https://larsbergqvist.wordpress.com/2017/08/07/using-ch340-devices-with-osx/

My CH340 driver was installed on a Mac a few OS versions ago.   I am running the Arduino IDE connecting to various CH340 devices without issue under Mac OS Sierra (I haven't updated to High Sierra for other reasons).

73 Mike ZL1AXG

--
Mike Woods
mhwoods@...




--
A blessing on your days. A blessing on your life. A blessing on the land.


Re: µBITX keyer pull up resistor without jack #ubitx

K9HZ <bill@...>
 

yup

 

 

Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

 

Owner - Operator

Big Signal Ranch – K9ZC

Staunton, Illinois

 

Owner – Operator

Villa Grand Piton – J68HZ

Soufriere, St. Lucia W.I.

Rent it: www.VillaGrandPiton.com

Like us on Facebook! facebook icon

 

Moderator – North American QRO Group at Groups.IO.

 

email:  bill@...

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Doug W
Sent: Saturday, April 28, 2018 5:55 PM
To: BITX20@groups.io
Subject: [BITX20] µBITX keyer pull up resistor without jack #ubitx

 

At this point I have no intention of using my µBITX for CW.  I understand I still need the pull up resistor between pins 2 and 3 on the Raduino.  I am trying to eliminate as many unnecessary wires as possible.  Couldn't I just connect a 4.7k resistor between the pins without using the jack or am I missing something?


Virus-free. www.avg.com


µBITX keyer pull up resistor without jack #ubitx

Doug W
 

At this point I have no intention of using my µBITX for CW.  I understand I still need the pull up resistor between pins 2 and 3 on the Raduino.  I am trying to eliminate as many unnecessary wires as possible.  Couldn't I just connect a 4.7k resistor between the pins without using the jack or am I missing something?


Re: Diagnostic software for uBitx #ubitx

John (vk2eta)
 

So far I have to say the Han's QCX concept is really neat. It uses 6 passive components and provides an on-board DC, AC/RF meter, RF power meter, frequency meter and signal generator. Brilliant.

That coupled with the measuring functions pre-loaded in software and an expected list of values seems the best value for money in debugging a radio's circuit and wiring.

The spare A7 input could be put to fair use in the wiring phase of the project before being used for whatever the user feels like.

In my view if the Arduino is not functional, then there is not much to test since the radio would not be functional. So this is assuming the Arduino is at least communicating . And if it is, but has defective analogue or digital input failures then one side value of the test would be to determine if the pain of going through its replacement is warranted or not.

But as suspect, recollecting the list postings, that wiring issues and possibly alignment issues are main problems so far.

The test software will be small enough to fit alongside the factory firmware if it is deemed of value. That and a few components could be of great value imho.

And a pre-loaded software would avoid what could be seen as a daunting task of setting the Arduino IDE and loading a software.

In the mean time, I'll keep coding and see how much we can extract of the current hardware.

All the best,

73, John (VK2ETA)


Re: No Speaker Audio #ubitx

iz oos
 

Check the wiring at the potentiometer. I indeed reversed two of them, so as switched on the volume was highest. Maybe that was one cause of the failing TDA without the WX mark. Volume is plenty as there is no agc when signals are strong.


Il 28/apr/2018 21:16, "W7PEA" <patrick@...> ha scritto:
I ordered new chips and sockets from Amazon and slow-shipping because its not an amazon fulfilled product and shipping was going to be multiples of the cost of the parts.... so no fun for a few weeks.

I'll post back when I have parts in hand and I am making progress again.


Re: mono band 2 meters rig based on the micro BITx circuit #ubitx #2meters

Tim Gorman
 

I agree with you. I have one on order.

If you already have a good IF system (i.e. the ubitx) why spend money
duplicating it?

tim ab0wr

On Sat, 28 Apr 2018 10:06:06 -0500
"K9HZ" <@Doc_Bill> wrote:

If such a radio is just CW and SSB, those ultra-cheap transverters
from the Ukraine are by far the best solution. If the radio will
operate FM… that’s where a redesign is required.



I’m using one of the transverters now and they work fine with some
simple interfacing.





Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ



Owner - Operator

Big Signal Ranch – K9ZC

Staunton, Illinois



Owner – Operator

Villa Grand Piton – J68HZ

Soufriere, St. Lucia W.I.

Rent it: www.VillaGrandPiton.com <http://www.villagrandpiton.com/>

Like us on Facebook! <https://www.facebook.com/VillaGrandPiton/>



Moderator – North American QRO Group at Groups.IO.



email: <mailto:@Doc_Bill> @Doc_Bill





From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Jerry
Gaffke via Groups.Io Sent: Saturday, April 28, 2018 9:58 AM
To: BITX20@groups.io
Subject: Re: [BITX20] mono band 2 meters rig based on the micro BITx
circuit #ubitx #2meters



Looks like the goal is to build something more challenging than the
uBitx. Beyond that what it is or does is totally up in the air.
Discussion seems to be moving toward a single band rig capable of
SSB/CW about uBitx size.

A few thoughts of my own:
Phase noise from that si5351 gets worse as the freq goes up, maybe an
si5338 or si5341? Having all oscillators off a single reference makes
calibration much easier. Could be used for cross band ops if it
receives on more bands than it transmits. A wideband receiver could
also be a spectrum analyzer, use digital techniques on the audio when
resolution better than the crystal filters is required. Transmit
mixer, drivers, final could be a separate board for each band
desired, zero transmit boards is an option for receive only.

Jerry


On Sat, Apr 28, 2018 at 05:55 am, Tim Gorman wrote:

I'm lost as to what your goal is here.
1. The baofeng won't do SSB. Are you wanting to build a SSB unit or an
FM unit?
2. Are you thinking of a handheld or a desktop?
3. a phase line at 432Mhz won't be correct for 144Mhz. Are you
thinking a two-band unit or one-band unit?





---
This email has been checked for viruses by AVG.
http://www.avg.com


Re: Diagnostic software for uBitx #ubitx

Tim Gorman
 

For me the easiest thing to do would be to have a socketed Nano (I
know - cost!). You could then plug in a second Nano with diagnostic
software to chase outboard problems. Inboard problems with the Nano are
probably not fixable (how does the nano tell if an on-board pull-up
resistor is bad vs the outside world causing what it sees?).

Out of the ten Nano's I've ordered I found one that did not work
right. It simply went in the trash can. Not worth trying to figure out
why when the next one worked ok. Substitution is a valid
troubleshooting tool.

tim ab0wr



On Sat, 28 Apr 2018 11:53:53 -0600
"Arv Evans" <arvid.evans@...> wrote:

Lawrence

I think the suggestion was to use a working Arduino board to help do
diagnostics on
an attached BITX transceiver. This would be different from expecting
a non-working
processor to diagnose itself. Question in this is whether the
Arduino/Raduino would
have built-in code for BITX diagnostics, or would it require a code
reload for the
Arduino to do this task.

While smaller mini-frame systems VAX, DEC, etc. used to have a single
processor
my experience with large mainframes (IBM-360, Bell Labs 4ESS, etc.)
had multiple
core processors and actually could, in some cases, do diagnostics on
limited parts
of the system. But this is way beyond what we are dealing with in
the BITX world
where a rather simple AVR Mega-328 micro-controller is all we have to
work with.

There have been earlier comments regarding Arduino based test
equipment that could
be designed and built such that it would be an accessory or separate
controller used
for diagnostic purposes, but this is more stand-alone test sets than
an internal
diagnostic element.

Arv K7HKL
_._


On Sat, Apr 28, 2018 at 11:26 AM, Lawrence Macionski via Groups.Io <
am_fm_radio=yahoo.com@groups.io> wrote:

40 years as a senior field engineer on big main frames and such..
Self diagnostic hardware and software is wonderful provided the
machine is actually working when you run the diagnostics. most
engineers who rely on diagnostics puke when they can't run them for
various reasons.

I have a few thousand airline miles "fixing" for instance a VAX
11/785 mainframe down for 3 days.. Can't boot, can't run
diagnostics. The 11/ 785 CPU was 29 24x24 inch boards, all were
changed. Even changed the microvax computer -boot loader. (a 8-12
board mini-computer w/ 8"floppy that loaded the mainframe
microcode). My Solution/findings: Every 8" floppy on site was bad,
the ones I brought worked just fine. Perhaps a disgruntled employee
demagnetized all floppies but the one that was loaded in the
loader. then it eventually went bad..(The perfect crime)

Drove all night- Detroit to Indianapolis once for a 1amp 5 volt
fuse..System down 3-4 days. (SUN Microsystems 3/xxx series
computers, had the 5 volt line to the optical mouse fused.) in
order to log in you had to move the mouse to the login window even
to log in as root. The local engineer even changed the MOBO- and
the new MOBO had no fuse in the fuse holder.. National Tech support
told him to keep checking the configuration berg jumpers never even
knew there was a fuse on the board.. The old MOBO had a blown
fuse.. BTW- Sun Microsystems never had a part number for that fuse
or even mentioned it in engineering documentation.. a 3rd MOBO
arrived by air courier as I was leaving. It did have a new good
fuse


If you've read this far. I have to ask this question:
uBITX are not $3000 radio's.. DXpeditions don't depend on 1 radio
but pack extra's. For the $120-180 we have invested in a working
rig, Isn't it realistic to invest in a second? I have multiple
rigs as perhaps I'm blessed. but there are times (close lightening
strike) that can render a uBITX or anyother rig perhaps unfixable.
Still they are fun aren't they?




Re: uBITX_CEC1.073_20I.hex

Bo Barry <bobarr@...>
 

I'm having problems uploading to my Nano since I did upload a hex file successfully. I cannot get even the blink example to load now. NADA. But the hex (avrdude) loader still will upload hex files. It must have busted the bootloader or something.


Re: Sideband Suppression (receive) #ubitx #ubitx-help

Tim Gorman
 

Arv,

I have a spectrum analyzer. I use a two-tone generator. There is no
issue with spurious microphone response. While the two-tone gen is
just a standard kit, I can't see any distortion on my oscilloscope in
either the time domain or in the frequency domain using the scopes
FFT math function. I'm sure there is some but not enough to cause
this carrier suppression figure. Nor are there any ultra-sonic tones
showing up on the spectrum scan, either at audio freq's or rf freqs.

Just a single tone from the two-tone generator and the carrier.

25db is the *best* I can get by adjusting the BFO. Standard adjustment
of the BFO gave about 18db to 22db. Moving the BFO down the filter
skirt gave me another 3db.

tim ab0wr

On Sat, 28 Apr 2018 11:13:53 -0600
"Arv Evans" <arvid.evans@...> wrote:

Tim AB0WR

Some earlier BITX transceivers did use a ring mixer but the carrier
suppression was
not noticeably better than with the present design. Allison's
comments are valid and
reflect a good place to start looking.

Placing the BFO down the edge of the crystal filter passband helps
improve carrier
rejection and improves audio by filtering off unneeded lower frequency
voice products.
You can tailor the lower frequency speech response by how far down the
filter skirt
you place the BFO.

If you have means to do spectrum analysis you can measure crystal
filter response
and use that information to determine where the BFO should be set.
If you do not
have spectrum analysis tools, it is still possible to do a manual
sweep by adjusting the
BFO in small (20 to 100 Hz) steps across the filter passband and plot
the filter output
using a diode detector and graph paper. Note that linear graph paper
will show an
expanded curve where log graph paper will show a more conventional
decibel curve.

If noise is being injected into the balanced modulator via the
microphone or microphone
amplifier it will not be possible to get a deep null in carrier
balance. It is conventional
practice to short the microphone input while doing carrier balance
adjustments and
measurement.

Allison's comment regarding possibility of undetected ultra-sonic
tones present that
can cause unwanted carrier insertion is something that we do not
usually look for.
A quick look at modulator AF input with an oscilloscope would
probably show any
such problem.

Typical crystal ladder filters usually show a steeper curve on its
lower sideband than
on the upper sideband. Some of the high-IF designs ignore that and
as a result will
show less carrier rejection on either USB or LSB, depending on the
design.

https://goo.gl/ZGf8wR

https://goo.gl/4Q8kCV

http://www.qsl.net/g3oou/iffilters1.html

<goog_592175929>

http://tinyurl.com/y7re23nn

Arv K7HKL
_._



On Fri, Apr 27, 2018 at 8:50 PM, Tim Gorman <tgorman2@...> wrote:

I've never been able to get over 25db of carrier rejection
according to my Rigol DSA815. Not unless I move the BFO so far that
signals are unintelligible. If you adjust by 6db to allow for PEP
equivalence this is still only 31db of rejection.

In looking at the modulator circuit I don't see much of a way to
increase carrier rejection without major butchery, i.e. totally
replacing the modulator with a ring mixer which would allow
providing for a carrier balance adjustment.

tim ab0wr

On Fri, 27 Apr 2018 18:22:21 -0700
"ajparent1/KB1GMX" <kb1gmx@...> wrote:

Two things result in carrier...

One is the BFO too close to or in the filter passband, it should
be 6-10 db down the edge of the filter. Blaming the filter will
not fix that, unless its seriously broken. NOTE: Each unit
will vary some on the best BFO setting this happens with
commercial filters too.

The other is imbalance in the modulator circuit. Solution is fix
it.

There is a remote possibility of a tone at higher than you can
here present in the tx due to a circuit or wiring issue.

Its not rocket science to measure the power out and the residual
carrier. a 50 ohm load, a diode detector is all that is needed
plus a voltmeter. Compare power out at full power and with no
audio at all the ratio in DB should be better than 40DB
(10,000:1) or for 10W out less than 1mW.

Allison




Re: show your mic

Michael Aiello
 

3d-printed body with stock mic element and switch

73
Mike N2HTT


Re: Diagnostic software for uBitx #ubitx

Dexter N Muir
 

Seconded, Dave!

I'm just a little younger (67, 51 a Ham) and am continually enthused, even if constrained. My Bitx-40 is stalled, and probably won't be finished - I've hopes of being able to afford a ubitx at some stage ...

73
Dex, ZL2DEX


Re: mono band 2 meters rig based on the micro BITx circuit #ubitx #2meters

Dexter N Muir
 

Yes, Jerry - a case of PEBCAK at the webage's creation. Lack of consultation with a competent Tech, and lack of knowledge of keyboard and capability of software commonly at hand. Any word-processor has Math symbols and can sub/superscript, so sqrt() can be () and **2 can be ^2 or 2 (shifted to LibreOffice Writer then copy-and-paste for them) - much more readable/comprehensible! Might be a good submission to the site?

73
Dex, ZL2DEX


Re: Please don't make Radiuno with CH340/CH341 chipsets any more! Or at least advertise that you do use them! #radiuno

Mike Woods
 

On 29/04/18 8:34 AM, ab2ts wrote:
I plugged the Radiuno into my Mac and tried to program it with the Arduino GUI and let loose with a few expletives.  I knew immediately what had happened.   I usually do my homework and avoid the CH34x chipsets in my Arduino projects, but Radiuno was not offered in another form and I neglected to check the chipset.    (I still haven't found a spec for Radiuno that says what chipset it uses; clearly it is a CH340.)

 I solved the problem by digging out a very old MacBookPro with an antique OS which does did not have the security feature and did support CH34x chipsets.  While it is slow, it fortunately it runs the latest version of Arduino.   My other alternative would have been to remove the CHxx Arduino Nano and replace it with an FTDI or Prolific PL2303 Arduino Nano...   I may do that yet am not looking forward to it.  

This may be a solution:

https://larsbergqvist.wordpress.com/2017/08/07/using-ch340-devices-with-osx/

My CH340 driver was installed on a Mac a few OS versions ago.   I am running the Arduino IDE connecting to various CH340 devices without issue under Mac OS Sierra (I haven't updated to High Sierra for other reasons).

73 Mike ZL1AXG

--
Mike Woods
mhwoods@...


Re: uBITX_CEC1.073_20I.hex

Jack, W8TEE
 

Why do you need the hex files when the source code is available?

Jack, W8TEE


On Saturday, April 28, 2018, 4:42:37 PM EDT, Bo Barry <bobarr@...> wrote:


For the life of me I can't find the compiled hex files. Help!

Bo W4GHV


uBITX_CEC1.073_20I.hex

Bo Barry <bobarr@...>
 

For the life of me I can't find the compiled hex files. Help!

Bo W4GHV


Please don't make Radiuno with CH340/CH341 chipsets any more! Or at least advertise that you do use them! #radiuno

ab2ts
 

For those Radiuno suppliers that do not know;  Macintosh users have significant trouble with the CH340/CH341 Arduino clones.    

The Chinese vendor that makes that chip has done a very poor job writing drivers for the Macintosh.   Many users report computer crashes and "kernel panics".    The most suggested solution is to bypass an important security feature of the Mac called System Integrity Protection.  This is definitely not recommended and requires some system level hacking that is beyond the average user.   Some users report that the Chinese driver works for them; most do not.   The latest driver from the Chinese (v1.4) does not require the system hack, but it does not connect to the Radiuno for me.  I do still get occasional system crashes when trying to upload.   

Apple supports just about all modern USB devices but it specifically does not provide drivers CH34x devices.  Clearly this is a security issue for them.  My understanding is that the CH34x devices were created to skirt royalties to be paid to the FTDI or Prolific intellectual property holders.  For one reason or another, Apple does not support them.   CURRENTLY (and despite claims to the contrary) THE AVAILABLE 3RD PARTY DRIVERS ARE UNRELIABLE.   

I plugged the Radiuno into my Mac and tried to program it with the Arduino GUI and let loose with a few expletives.  I knew immediately what had happened.   I usually do my homework and avoid the CH34x chipsets in my Arduino projects, but Radiuno was not offered in another form and I neglected to check the chipset.    (I still haven't found a spec for Radiuno that says what chipset it uses; clearly it is a CH340.)

 I solved the problem by digging out a very old MacBookPro with an antique OS which does did not have the security feature and did support CH34x chipsets.  While it is slow, it fortunately it runs the latest version of Arduino.   My other alternative would have been to remove the CHxx Arduino Nano and replace it with an FTDI or Prolific PL2303 Arduino Nano...   I may do that yet am not looking forward to it.  

Please no more CH34x chipsets!

Thanks


Re: LCD display too dark

Ronald Payne <wb5klj@...>
 

Yes, a slight tweek on the pot made a great improvement in my displays read ability.


Re: No Speaker Audio #ubitx

W7PEA
 

I ordered new chips and sockets from Amazon and slow-shipping because its not an amazon fulfilled product and shipping was going to be multiples of the cost of the parts.... so no fun for a few weeks.

I'll post back when I have parts in hand and I am making progress again.


Re: Diagnostic software for uBitx #ubitx

Joe Puma
 

I took apart a Sun Microsystems mainframe while I was studying Digital Electronics in tech school 1 block from 42nd street in Manhattan in the late 80’s. I was too young for the mainframe era but I love hearing stories about it. 

73’s
Joe
KD2NFC 



On Apr 28, 2018, at 1:26 PM, Lawrence Macionski via Groups.Io <am_fm_radio@...> wrote:

40 years as a senior field engineer on big main frames and such.. Self diagnostic hardware and software is wonderful provided the machine is actually working when you run the diagnostics. most engineers who rely on diagnostics puke when they can't run them for various reasons.

I have a few thousand airline miles "fixing" for instance a VAX 11/785 mainframe down for 3 days.. Can't boot, can't run diagnostics. The 11/ 785 CPU was 29 24x24 inch boards, all were changed. Even changed the microvax computer -boot loader. (a 8-12 board mini-computer w/ 8"floppy that loaded the mainframe microcode). My Solution/findings: Every 8" floppy on site was bad, the ones I brought worked just fine. Perhaps a disgruntled employee demagnetized all floppies but the one that was loaded in the loader. then it eventually went bad..(The perfect crime)

Drove all night- Detroit to Indianapolis once for a 1amp 5 volt fuse..System down 3-4 days. (SUN Microsystems 3/xxx series computers, had the 5 volt line to the optical mouse fused.) in order to log in you had to move the mouse to the login window even to log in as root. The local engineer even changed the MOBO- and the new MOBO had no fuse in the fuse holder.. National Tech support told him to keep checking the configuration berg jumpers never even knew there was a fuse on the board.. The old MOBO had a blown fuse.. BTW- Sun Microsystems never had a part number for that fuse or even mentioned it in engineering documentation.. a 3rd MOBO arrived by air courier  as I was leaving. It did have a new good fuse


If you've read this far. I have to ask this question:
uBITX are not $3000 radio's.. DXpeditions don't depend on 1 radio but pack extra's. For the $120-180 we have invested in a working rig, Isn't it realistic to invest in a second?  I have multiple rigs as perhaps I'm blessed. but there are times (close lightening strike) that can render a uBITX or anyother rig perhaps unfixable.  Still they are fun aren't they?