Re: Ordering date, shipping date, Ordering date, received date
Ken
The ordering, shipping, and delivery dates are used to optimize product delivery
procedures.? Need for this may decrease once backlog situation is resolved but
there will probably still be some interest because it tells purchasers what to expect
in shipping delays and which carrier might be the best to choose when you order
a BITX.
Arv? K7HKL
_._
On Fri, Mar 16, 2018 at 1:28 PM, Ken Brown <n4so.ken@...> wrote: There are multiple messages on BITX of an ordering date, shipping date, or ordering date and received my BITX date.? Do you think everyone wants to know your ordering date, shipping date, or your received date, or your not-received date of your BITX?
Ken
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Ordering date, shipping date, Ordering date, received date
There are multiple messages on BITX of an ordering date, shipping date, or ordering date and received my BITX date.? Do you think everyone wants to know your ordering date, shipping date, or your received date, or your not-received date of your BITX?
Ken
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I have to wonder what is going on here!? I ordered mine February 1st and have gotten no shipping notification yet.? Are they not shipping in order?
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Re: Soldering gun or iron
How do you apply the paste? I dont have a way to create a mask for a pcb. You also make a good point. If you have a heat gun you can use shrink wrap. Thats a great reason to get a hot air rework station with an iron.
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Before applying power - recommended changes
I see discussions about issues with the audio chip and how applying power to the uBITX might fry the chip. I also see there is a workaround with a voltage regulator.
Having just received my uBITX (with the WX version?of the TDA2822M audio chip); I would like to know if there is a list of fixes, mods or recommended changes one should verify and/or apply BEFORE applying power for the first time?
--
John WA1KLI
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Re: Soldering gun or iron
Having a hot air gun available for tighter pitch work is important. Spark fun has an old multi page tutorial on SMD work located at? . Is it possible to use just an iron? Sure, and again it depends on the work that will be done. However, if you look at the page for removing multi pin SMD ICs you can see the results of trying to without hot air. You can try and physically force them out of place or use an xacto knife to try and cut the pins. Both are bad because just flexing the part can rip a pad out which means you will need forceps and wire to fix it, or you can cut traces with the knife. The best thing to do if any rework or SMD parts need to be placed is to get the right tool for the job which is a hot air rework station. I have seen people suggesting 100$ irons. Well, if you spend the 70$ on a rework station you wont have that problem... This again is all based on the assumption that this person will need to work on the UBitx or mods or possibly other kits. Sure its another 50 bucks or so, but it will save hours of frustration for a person who hasn't even used an iron in a long time.
Chris KF4FTR
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Re: Micro BitX No Audio TDA2822?
Hi, i have think if there come some tones to the input of TDA2822 on a frequency we could not hear, 20 KHz or perhaps a lower, with much higher power, than the normal wanted sound. That could burn the TDA2822. Perhaps a LP filter about 2.5 KHz in front of the volume control would be good. Just an idea. 73, Stig, oz8pz
Some of these clones seem to blow for no particular reason.
I think we primarily must limit the supply voltage, not so much the current under load.
Though they are really good at dealing with variations in supply voltage.
The series resistor in the 12v supply could be a solution for a good (non WX)?TDA2822
if you are worried about exceeding the max power dissipation spec at high volume
and low load impedance.
On Thu, Mar 15, 2018 at 07:22 pm, Jerry Gaffke wrote:
Quiescent current into the TDA2822 is around 6ma, peaks can be 1 Amp.
Though?100ma might be sufficient for moderate speaker volumes.
You would need two resistors for a voltage divider, and maybe waste 500 ma through them
to keep the voltage moderately well regulated.
Good spot for an LM7805.
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Crystal ladder filters tend to have a steeper skirt on the upper freq side than on the lower freq side as Tim suggests.
See fig 3 here:??
Other than that, I disagree.
I'd say that unless other factors override this, the BFO frequency is better off above the crystal filter
to get maximum opposite sideband rejection, using the sharper skirt on the upper side.?
This also maximizes carrier suppression, though with a balanced modulator this may not be
a primary consideration.? Once you get rid of the opposite sideband, you can shape the signal
further with audio filters, though this generally isn't needed.
With the 6 pole crystal filter on the uBitx, both skirts are fairly sharp, much better than the Bitx40.
So having the BFO above or below the crystal filter works well enough.
A second consideration is that the local oscillators should be above the intermediate frequency.
On the uBitx, we have the VFO above the 45mhz first IF, for a 7.2mhz signal the VFO is 7.2mhz above 45mhz.
With the high side VFO, all VFO harmonics are up in VHF and beyond, and products of those harmonics are
more easily gotten rid of.?
On the uBitx, clk1 would best be 12mhz above the 45mhz first IF, to create a 12mhz
signal into the second IF.? However, on the uBitx we have the further issue of Nano 16mhz and 12mhz oscillator
harmonics?mixing with?BFO harmonics, creating those audio tones the some posts here have complained about,
so we leave the?BFO below the 12mhz crystal filter and use have clk1 above 45mhz for USB, below 45mhz or LSB.
Jerry, KE7ER
toggle quoted message
Show quoted text
On Fri, Mar 16, 2018 at 01:00 am, Tim Gorman wrote:
One thing to remember is that crystal filters have always been
considered to be *upper* sideband filters primarily.
They don't have infinitely steep firewalls at each end of the bandpass.
Think of a crystal filter having a slope of 60deg on the low frequency
side and a 45deg slope on the upper frequency side. It's not that
bad but it illustrates the point.
The filter works best when the carrier is on the low frequency side of
the crystal and the audio is above the carrier. The high frequencies in
the voice are usually lower in power anyway so the increased slope on
the upper frequency side of the filter still provides adequate
attenuation.
If you switch and put the carrier on the upper frequency side of the
filter and the audio lower in frequency than the carrier then you are
using your filter where it works the worst. It's not so bad for
transmitting other then it doesn't suppress the carrier as well but for
receiving it tends to let low frequency noise *and* signal through more
than if you use it as an upper sideband filter.
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Re: Soldering gun or iron
I've used that embossing heat gun for a couple of years with soldering paste and it works well. Day to day use is mostly heat shrink tubing. Good value for the price.
Roy WA0YMH
On Mar 16, 2018 12:46 PM, "Jerry Gaffke via Groups.Io" <jgaffke= [email protected]> wrote: I think I could be quite happy with a $20 pencil iron for SMD work.
A temperature control knob is not important, though having one suggests it has a thermostat which is important.
Otherwise you will burn the tip out when you leave it sit for a few minutes.
I usually fling the knob all the way to the upper stop so I have a nice hot iron, control heat by not applying it so long.
A relatively cold tip is quite common, and impossible to do good work with.
A clean tip is important, should see molten solder flow everywhere around the tip.
And when working with 0.5mm pin pitch SMD parts, it had better be a pretty darn small tip.
A $15 embossing gun and tweezers is probably all you need for removing SMD IC's (I don't have this one):
? ?
Cover nearby parts with tinfoil or paper tape.
Don't tug at the part before the solder is molten or you will lift the copper pads off of the board.
Consider some ChipQuik:? ?
Many of the solders available now have no lead, these melt at higher temps and are harder to work with.
I stick with traditional leaded solder for hobbyist work, most of it 1mm in dia, sometimes? go through maybe a pound per decade if that.
If buying liquid flux, read up first.? Some of it is extremely corrosive.
A semi-professional rework station with a dozen tips and solder sucker might be nice,
but hardly necessary for occasional use.
Jerry, KE7ER
On Fri, Mar 16, 2018 at 08:42 am, Christopher Miller wrote:
Thats true, Farhan is correct that is the most important factor. Keeping the tip clean and tinned, as well as having the tip be quality is in my experience as well the most important as well. I believe the second should be temperature control. If you are going to buy a 100$ iron you might as well get a rework station? I checked again and tips and elements of the station are available. The PID loop cycles a couple times a second and works.
?
Its true I put through hole kits together with garbage but having a proper iron / station improved my work a lot.?
?
If a person will be doing work reasonably regularly paying 60-70 for a decent station with smd growing in popularity makes sense. You can salvage parts by using the hot air gun and tapping them to get the surface tension of the leaded solders surface tension to pull the part in to place.
?
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Re: Soldering gun or iron
I think I could be quite happy with a $20 pencil iron for SMD work.
A temperature control knob is not important, though having one suggests it has a thermostat which is important.
Otherwise you will burn the tip out when you leave it sit for a few minutes.
I usually fling the knob all the way to the upper stop so I have a nice hot iron, control heat by not applying it so long.
A relatively cold tip is quite common, and impossible to do good work with.
A clean tip is important, should see molten solder flow everywhere around the tip.
And when working with 0.5mm pin pitch SMD parts, it had better be a pretty darn small tip.
A $15 embossing gun and tweezers is probably all you need for removing SMD IC's (I don't have this one):
? ?
Cover nearby parts with tinfoil or paper tape.
Don't tug at the part before the solder is molten or you will lift the copper pads off of the board.
Consider some ChipQuik:? ?
Many of the solders available now have no lead, these melt at higher temps and are harder to work with.
I stick with traditional leaded solder for hobbyist work, most of it 1mm in dia, sometimes? go through maybe a pound per decade if that.
If buying liquid flux, read up first.? Some of it is extremely corrosive.
A semi-professional rework station with a dozen tips and solder sucker might be nice,
but hardly necessary for occasional use.
Jerry, KE7ER
toggle quoted message
Show quoted text
On Fri, Mar 16, 2018 at 08:42 am, Christopher Miller wrote:
Thats true, Farhan is correct that is the most important factor. Keeping the tip clean and tinned, as well as having the tip be quality is in my experience as well the most important as well. I believe the second should be temperature control. If you are going to buy a 100$ iron you might as well get a rework station? I checked again and tips and elements of the station are available. The PID loop cycles a couple times a second and works.
?
Its true I put through hole kits together with garbage but having a proper iron / station improved my work a lot.?
?
If a person will be doing work reasonably regularly paying 60-70 for a decent station with smd growing in popularity makes sense. You can salvage parts by using the hot air gun and tapping them to get the surface tension of the leaded solders surface tension to pull the part in to place.
?
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Re: uBitx low signals on the speaker
Thanks Ron for the info.
Here the audio circuit is finally ok, everything tested and working.
But ubitx continues with output level on the speaker very low. I have to increase the volume at maximum to receive medium and weak signals.
Now I suspect that it may be a problem in the detector, more precisely the level of the BFO that comes from the SI5351, or the other clock's.
Take the tests here.
?
73 from Junior
PY2ADA
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Re: Soldering gun or iron
Can't resist this story: I was at my rather remote shack in Alaska with limited tools.? The brand-new ICOM mic for my old 725 had a bad connection in the PTT circuit.? Of course I took it apart to fix, and, of course, the broken wire was that smaller-than-a-hair stuff.? With no soldering iron, I had to improvise.? Propane torch on the bench heating a #16 nail held by vise grips supported by the bench vise, using big plumbing-size solder.? Mic works to this day.? Lucky I didn't burn the shack down.....Those 3-in-1 rework stations look pretty tempting....Aloha, Steve WH6ST
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It's HERE ordered Feb 11 received Mar 16
Fantastic!
On ?Friday?, ?March? ?16?, ?2018? ?01?:?30?:?21? ?AM? ?CDT, Chuck, N1KGY <cwayers12@...> wrote:
>I got mine yesterday also,? ordered 2/17.
This is exciting news - I ordered mine on 2/19.
As for the 2822 chips, I've decided to put a regulator in their B+? line before ever powering them up.
Thanks!
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Re: Blew the irf510's up, substituted irfp260's in there place...
#ubitx-help
My finals blew due to a bad load and testing out the PA on higher voltage supply. My own fault here.
--
----------
N5WLF, Greggory (or my nickname, Ghericoan)
General Class, Digital Radio Hobbyist
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Re: Blew the irf510's up, substituted irfp260's in there place...
#ubitx-help
I keep seeing that many people seem to be having problems with the IRF510's in their uBITX radios, but that hasn't been my experience here at all.
I have 3 uBITX's, one from each of the first 3 batches. ?Of all 3 kits, only the one from the third batch has given me any grief and that was due to the WX branded audio chip. ?Fortunately I had some UTC branded ones on hand and since replacing it have had no problems whatever.
I have always operated my uBITX radios into antennas that had less than a 2:1 SWR but I wasn't particularly careful except that I always had an antenna of some sort or a dummy load connected to them when I first powered them up just in case they started transmitting due to a shorted key line or some other problem. ?I did not change the factory settings for PA Bias or the power controls, I just left them where they were set from the factory's final test.
Either I was just lucky, or maybe that due diligence (antenna or dummy load connected before powering up) has kept me from having problems with the PA transistors. ?I am getting 10 or more watts out of each of the radios on 80-20 meters and about 7 watts on 10 meters with all three radios which falls in line with statements on the HF Signals web page about the uBITX. ?
OH yes, the first thing I did on all three kits was use thermal insulators and insulated bushings to mount the IRF510's to their heat sinks. ?This way if something grounded contacts one or both heat sinks it doesn't blow the transistor. ?
Just my 2 cents on the subject.?
Jim Sheldon, W0EB?
------ Original Message ------
Sent: 3/16/2018 11:09:57 AM
Subject: Re: [BITX20] Blew the irf510's up, substituted irfp260's in there place... #ubitx-help
It seems that just blindly replacing blown IRF510 devices with more IRF510's
is an exercise in treating the symptom instead of fixing the problem.? There
are many ideas and myths about why the IRF510 devices sometimes fail but
only limited definitive information on what actually causes these failures.?
We have empirical information indicating that if the SWR is high they will fail,
but limited information on exactly why that is the case and what the mechanism
of failure really is.
These URLs may help, or may not:
Arv? K7HKL
_._
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Re: Ubitx audio debug question
Hi Tim,
The TDA2822M's I got from Gateway Electronics had SSS 88737 no FCI or WX.? The sales person said this was a manufacture date code?of 1988.
He stated that these IC's must be better than the newer?FCI or WX types. ?I removed the bad TDA2822M and installed an IC socket in U1 on the board.
I installed?one of these new IC's ?and the?Ubitx is?working great again.? I tried transmitting and only have 2 watts out on 30 meters. I may need to peak
the output power.
73, Rod
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Had some computer problems and the earlier files were corrupted. ?Only way to correct them is delete the file and re-upload them -- sorry for the confusion. ?New computer on-line now and the old one retired to the basement. ?Hopefully won't have any more crashes.
Jim Sheldon
------ Original Message ------
Sent: 3/16/2018 11:08:16 AM
I have now gotten this message 4 times.?? What is going on?
Ron W7HD
Hello,
This email message is a notification to let you know that a
file has been uploaded to the Files area of the [email protected]
group.
File: ubitx_I2C2L_V3_00R.zip
Uploaded By:
Jim Sheldon <w0eb@...>
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Re: Blew the irf510's up, substituted irfp260's in there place...
#ubitx-help
It seems that just blindly replacing blown IRF510 devices with more IRF510's
is an exercise in treating the symptom instead of fixing the problem.? There
are many ideas and myths about why the IRF510 devices sometimes fail but
only limited definitive information on what actually causes these failures.?
We have empirical information indicating that if the SWR is high they will fail,
but limited information on exactly why that is the case and what the mechanism
of failure really is.
These URLs may help, or may not:
Arv? K7HKL
_._
On Thu, Mar 15, 2018 at 10:59 PM, John Backo <jabac@...> wrote: These HEXFETS are rated for 200V and 50A. They will (sorta) work as you have shown.
But the gate input capacitance is 4000+ pF. That increases your standing wave in
the drive circuit and lowers your output considerably. You have 2 choices:
Either replace the finals with IRF510s (after you have figured out what blew them up),
or figure out how to lower the input capacitance to 180 pF. or so. You can also probably
safely use a drain voltage of 48v or so, but there would probably be oscillation which would
have to be accounted for. Incidentally, how do you know they are not oscillating now?
Since the potential drain amperage is so high, it is probably wise to provide a current limiter
if you have not already done so, especially using wspr or another more or less continuous
wave function.
It's better to replace the finals.
john
AD5YE
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I have now gotten this message 4 times.?? What is going on?
Ron W7HD
toggle quoted message
Show quoted text
Hello,
This email message is a notification to let you know that a
file has been uploaded to the Files area of the [email protected]
group.
File: ubitx_I2C2L_V3_00R.zip
Uploaded By:
Jim Sheldon
|
Hello,
This email message is a notification to let you know that a file has been uploaded to the Files area of the [email protected]
group.
File: ubitx_I2C4L_V3_00R.zip
Uploaded By:
Jim Sheldon
Description:
W0EB/W2CTX latest firmware release for I2C equipped uBITX transceivers. Had some computer problems and files got corrupted.
Bad files were deleted and uploaded again with corrections plus I added a compiled HEX file. This version works on ANY I2C enabled Raduino card with an I2C 2 line x 16 character display if you follow the instructions and works especially well on our "RadI2Cino" card (available from W0EB - email via the email listed on QRZ please, not on the group forum for details on the RadI2Cino) This is the FOUR line display version with fully implemented CAT and interrupt driven CW - swappable paddle selection, Iambic A and B keyer modes. Completely rewritten alignment mode that has proven to be quite accurate as well.
You can access this file at the URL:
/g/BITX20/files/ubitx_I2C4L_V3_00R.zip
Cheers,
The Groups.io Team
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JonnyBoats (WA1KLI)
J¨²nior PY2ADA
Steve
Ghericoan
Jim Sheldon