Re: Using IRF530 outputs and 2N3553 drivers in ubitx
THe problem with grounded gate using Mosfets is twofold.
At 2A with a gm or 2-4S th input impedance would be under 2 ohms.? The second issue is the drain
to source reverse diode plus the high source to drain capacitance.? Stability might be an issue.
as to gain its determined by the product of inpu tto output impedances and for 10W level
we are limited for both, I'd expect a gain under 5-7db.
Gate capacitance is not a limiting factor.? I use BLF278 at 2M and the input capacitance is
about 400PF and that is for a very high performance VHF LDMOS FET (300-400W out!).
Gain up there is such that for full 350W out I need under 5W in.? How about 8 IRF510s
set up as 4x4 push-pull for 6M?? The input impedance is around 6 ohms and matched?
that amp?easily does over 200W at 28V.? ?The input transformer is 9:1 (3:1 turns) from
50 ohms to about 6 ohms.
The problem is matching the RF impedance, if done it performs.? At low HF its not as big
an issue as upper HF.? The greater than 10:1 range means the driver has to be able to
push enough power into a wide range of impedances or the matching circuit between
them is sufficient to over come that.? Its not as bad as it sounds.?
The basics for MOSFET amps is the impedance is not infinite even though at DC it is.
So the path to power is pick a fet with high Gm (most mosfets are very high gain)
and load the input for stability and to force the driver to impress enough voltage?
across the effective load.? Usually that means a low impedance.
Allison
|
who is going to be the first to have a water cooled BITX? - warning time waster
I have a cheap USB fan blowing at my stock heat sinks and they stay nice and cool when working digital.? But why settle for good enough?? Who wants to be the first to have a water cooled BITX?
Before anybody gets cranky I am about 49% kidding and I warned you in the subject.
--
|
Follow the three steps of mechanical diagnostics.
If it's stuck, hit it with a hammer.
If it breaks, it needed replacement anyway.
If you're going to throw it away, taking it apart won't do any more damage.
toggle quoted message
Show quoted text
On 5/18/2018 4:38 PM, Tim Gorman wrote: Mike,
Before you throw the encoder away is it sealed or does it have an
opening somewhere? You could try flushing it with WD40 to see if one of
the mechanical switches is hanging and just needs a little cleaning.
Blow it out good with air and let it dry for a while and then test it
again.
BTW, I did take one apart several years ago. It wasn't hard. I never
bothered to put it back together again tho!
tim ab0wr
On Fri, 18 May 2018 15:07:00 -0400
"Mike aka KC2WVB" <rb5363@...> wrote:
Thanks for addressing this issue, Daniel
I would show a picture of the encoder but I removed it. It's only a
few wires with yellow being a raduino ground that goes to the middle
pin out on the three pin out side. Yellow also goes to the top pin
out when viewing the encoder from its non-shaft side and the two pin
outs are on the left side of the encoder. Red then attaches below
yellow on the two pin out side and the remaining black and brown
wires attach to the top and bottom pin outs on the three pin out
side. Here it really does not matter because if you switch black and
brown you get reverse direction but I placed black on top and brown
on the bottom when looking at the encoder from behind and with the
three pin outs on the right side.
However, remember even if the push feature was perfect the rotary
feature of the encoder was only operating half correctly. I.e. the
pin out for the brown wire stayed at a constant high state while
rotating the shaft in any direction. I think it was 4.54 volts dc.
The push feature under a voltage test was erratic, so much so that I
don't really know how to easily verbalize its behavior. Regardless, I
should have something other than strictly two items that read "Band
Select" without an ability to select a band and "Press to Confirm"
which is not meaningful if a band is not able to be selected when the
encoder shaft is pushed inward. As a matter of fact there is a host
of menu items that are selectable by the encoder but it is not
presumably letting me in.
I am 99% certain the encoder that came with the kit was meant to be
in the manufacturers trash pile and I will know for certain the
encoder is the only issue my kit has when the new encoders arrive,
most likely, Monday.
I am building the sister radio, BitX 40, now. It does not use a rotary
encoder to tune the radio, rather it uses a 10K potentiometer. I
suppose this is because it being a single band radio needs not a menu
function that allows the operator to make changes. I am thinking,
until the new encoder arrives I can probably get some tuning along
the band its stuck on, ie 40 meters, by using a 10K potentiometer in
lieu of the encoder. What do you think of the Idea??
Thanks for your interest.
Mike
On May 18, 2018 2:03 PM, "Daniel Conklin" <danconklin2@...>
wrote:
Mike, It appears to be doing what it's supposed to do when you press
it. Post a photo of the back showing how you have it wired.
Daniel, W2DLC
|
Re: TDA2822 Smoke and FT8 Duty Cycle?
I put about a 5 ohm resistor in the wire coming from the ubitx going to the speaker jack just to try and eliminate that type of problem.
On Fri, May 18, 2018 at 4:41 PM, RowlandA <rarcher@...> wrote: I managed to let the smoke out of my TDA2822 this morning.? I built cables yesterday to connect the uBitx to my YCCC SO2R box so I could use my common headset and paddle / Winkey, and all was well with SSB and CW.? This morning I hooked up a USB sound dongle to the mic and phone jacks and made three FT8 QSO's before I noticed some nice wisps of grey smoke escaping from the uBitx case.??
I assumed it was the IRF510's from the FT8 duty cycle, but on opening the case I saw that the TDA2822 was cracked.? I read up on uBitx.net and saw that one of the causes of this failure is a mono phone plug in the stereo phone jack.? Sure enough, the phone plug I was using was mono.? It blew the AC power fuse as well (3A fast blow that comes with the Amateur Radio Kits of IN case).??
It's not the WX version of the TDA2822, so I believe it's my fault, not a faulty part.
I ordered a couple of NJM2073D's from Mouser (uBitx.net pointed out they are a pin compatible TDA2822 equivalent), and some IRF510's just in case.
Hopefully there's no hidden damage.? Which brings me to two questions:
1)? Assuming the problem was the mono plug shorting out the two outputs of TDA2822, is it likely that there was any other damage?
2)? This is a stock uBitx with stock heatsinks.? Can I run FT8 with its 50% duty cycle (worst case 15 sec TX / 15 sec RX) at full power???
73,
Rowland K4XD
|
TDA2822 Smoke and FT8 Duty Cycle?
I managed to let the smoke out of my TDA2822 this morning.? I built cables yesterday to connect the uBitx to my YCCC SO2R box so I could use my common headset and paddle / Winkey, and all was well with SSB and CW.? This morning I hooked up a USB sound dongle to the mic and phone jacks and made three FT8 QSO's before I noticed some nice wisps of grey smoke escaping from the uBitx case.??
I assumed it was the IRF510's from the FT8 duty cycle, but on opening the case I saw that the TDA2822 was cracked.? I read up on uBitx.net and saw that one of the causes of this failure is a mono phone plug in the stereo phone jack.? Sure enough, the phone plug I was using was mono.? It blew the AC power fuse as well (3A fast blow that comes with the Amateur Radio Kits of IN case).??
It's not the WX version of the TDA2822, so I believe it's my fault, not a faulty part.
I ordered a couple of NJM2073D's from Mouser (uBitx.net pointed out they are a pin compatible TDA2822 equivalent), and some IRF510's just in case.
Hopefully there's no hidden damage.? Which brings me to two questions:
1)? Assuming the problem was the mono plug shorting out the two outputs of TDA2822, is it likely that there was any other damage?
2)? This is a stock uBitx with stock heatsinks.? Can I run FT8 with its 50% duty cycle (worst case 15 sec TX / 15 sec RX) at full power???
73,
Rowland K4XD
|
Re: Winlink configuration with the uBitx
I do get tones in the passband on 20 meters. But its never been enough to wreck havoc on psk or ft8. Just a minor annoyance when I listen to the digi transmissions.
On Fri, May 18, 2018, 4:34 PM Jerry Gaffke via Groups.Io <jgaffke= [email protected]> wrote: Lucky you.
Those 12 and 16 mhz resonators on the Nano are not very accurate, could be spot on
or could be several thousand ppm off.? If close to spot on, you can get audio beat notes
with our 12mhz BFO.? Doesn't happen very often though.
On Fri, May 18, 2018 at 01:18 pm, Ghericoan wrote:
I use the usb for cat control and do not have too much trouble. Sure it raises the local receiver noise a small bit, but its not enough to worry about.
--
----------
N5WLF, Greggory (or my nickname, Ghericoan)
General Class, Digital Radio Hobbyist
|
Mike, Before you throw the encoder away is it sealed or does it have an opening somewhere? You could try flushing it with WD40 to see if one of the mechanical switches is hanging and just needs a little cleaning. Blow it out good with air and let it dry for a while and then test it again. BTW, I did take one apart several years ago. It wasn't hard. I never bothered to put it back together again tho! tim ab0wr On Fri, 18 May 2018 15:07:00 -0400 "Mike aka KC2WVB" <rb5363@...> wrote: Thanks for addressing this issue, Daniel
I would show a picture of the encoder but I removed it. It's only a
few wires with yellow being a raduino ground that goes to the middle
pin out on the three pin out side. Yellow also goes to the top pin
out when viewing the encoder from its non-shaft side and the two pin
outs are on the left side of the encoder. Red then attaches below
yellow on the two pin out side and the remaining black and brown
wires attach to the top and bottom pin outs on the three pin out
side. Here it really does not matter because if you switch black and
brown you get reverse direction but I placed black on top and brown
on the bottom when looking at the encoder from behind and with the
three pin outs on the right side.
However, remember even if the push feature was perfect the rotary
feature of the encoder was only operating half correctly. I.e. the
pin out for the brown wire stayed at a constant high state while
rotating the shaft in any direction. I think it was 4.54 volts dc.
The push feature under a voltage test was erratic, so much so that I
don't really know how to easily verbalize its behavior. Regardless, I
should have something other than strictly two items that read "Band
Select" without an ability to select a band and "Press to Confirm"
which is not meaningful if a band is not able to be selected when the
encoder shaft is pushed inward. As a matter of fact there is a host
of menu items that are selectable by the encoder but it is not
presumably letting me in.
I am 99% certain the encoder that came with the kit was meant to be
in the manufacturers trash pile and I will know for certain the
encoder is the only issue my kit has when the new encoders arrive,
most likely, Monday.
I am building the sister radio, BitX 40, now. It does not use a rotary
encoder to tune the radio, rather it uses a 10K potentiometer. I
suppose this is because it being a single band radio needs not a menu
function that allows the operator to make changes. I am thinking,
until the new encoder arrives I can probably get some tuning along
the band its stuck on, ie 40 meters, by using a 10K potentiometer in
lieu of the encoder. What do you think of the Idea??
Thanks for your interest.
Mike
On May 18, 2018 2:03 PM, "Daniel Conklin" <danconklin2@...>
wrote:
Mike, It appears to be doing what it's supposed to do when you press
it. Post a photo of the back showing how you have it wired.
Daniel, W2DLC
-- tim ab0wr
|
Re: Winlink configuration with the uBitx
Lucky you.
Those 12 and 16 mhz resonators on the Nano are not very accurate, could be spot on
or could be several thousand ppm off.? If close to spot on, you can get audio beat notes
with our 12mhz BFO.? Doesn't happen very often though.
toggle quoted message
Show quoted text
On Fri, May 18, 2018 at 01:18 pm, Ghericoan wrote:
I use the usb for cat control and do not have too much trouble. Sure it raises the local receiver noise a small bit, but its not enough to worry about.
|
I bought some off ebay , not for the ubix, but to play with.? They have the 'clicks'.? I did see where someone had modified them to take out the clicks.? You could probably do the same .
On Fri, May 18, 2018 at 3:57 PM, kj6etl <pa1zz@...> wrote: I just bought these but I can feel clicks (steps) while turning. Does this mean they send me a part that isn't an EC11?
What else do I need to search for? I prefer a North American vendor for fast shipment.
This is what I just received.
_._,_._,_
|
I disabled the clicks by disassembling the encoder and ripping of the little clicker ring.
First bend the four metal tabs away from the back plastic cover.
Let the whole thing fall apart, being careful to note in what order.
There's a metal ring with a couple raised bumps spot-welded to the front metal frame (as I recall),
rip that ring out of there with a pair of pliers and a good strong tug.
Re-assemble.
I would have been fine with the mechanical clicks, except they were not quite aligned
with the encoder switch contacts so some of the clicks behaved differently.
Also, using the uBitx stock code, I was getting 4 counts per click (most of the time),
so without the clicks I have 4 times the resolution.
Works great now that it has been modified.
And if it doesn't, just remember that they are really cheap.
Jerry
|
Mike it appears that your encoder was setup properly as you described. With the first press of the encoder get you into the menus at this point if you rotate the encoder knob you will step through various selections. At this point you will need to press the encoder again to select that menu item using your example of band select if you rotate the encoder knob now it will step through the bands/frequencies in large steps the upper line will say Press to Confirm while the lower line will change with each step. Press the encoder knob now will save the selection on the lower line of the display. I hope this will help but sorry to hear you already removed the encoder.
toggle quoted message
Show quoted text
On May 18, 2018, at 15:07, Mike aka KC2WVB < rb5363@...> wrote: Thanks for addressing this issue, Daniel
I would show a picture of the encoder but I removed it. It's only a few wires with yellow being a raduino ground that goes to the middle pin out on the three pin out side. Yellow also goes to the top pin out when viewing the encoder from its non-shaft side and the two pin outs are on the left side of the encoder. Red then attaches below yellow on the two pin out side and the remaining black and brown wires attach to the top and bottom pin outs on the three pin out side. Here it really does not matter because if you switch black and brown you get reverse direction but I placed black on top and brown on the bottom when looking at the encoder from behind and with the three pin outs on the right side.?
However, remember even if the push feature was perfect the rotary feature of the encoder was only operating half correctly. I.e. the pin out for the brown wire stayed at a constant high state while rotating the shaft in any direction. I think it was 4.54 volts dc.
The push feature under a voltage test was erratic, so much so that I don't really know how to easily verbalize its behavior. Regardless, I should have something other than strictly two items that read "Band Select" without an ability to select a band and "Press to Confirm" which is not meaningful if a band is not able to be selected when the encoder shaft is pushed inward. As a matter of fact there is a host of menu items that are selectable by the encoder but it is not presumably letting me in.
I am 99% certain the encoder that came with the kit was meant to be in the manufacturers trash pile and I will know for certain the encoder is the only issue my kit has when the new encoders arrive, most likely, Monday.
I am building the sister radio, BitX 40, now. It does not use a rotary encoder to tune the radio, rather it uses a 10K potentiometer. I suppose this is because it being a single band radio needs not a menu function that allows the operator to make changes. I am thinking, until the new encoder arrives I can probably get some tuning along the band its stuck on, ie 40 meters, by using a 10K potentiometer in lieu of the encoder. What do you think of the Idea??
Thanks for your interest.
Mike
|
I just bought 5 rotary encoders from Digi Key for $1.68?each. The part number is PEC11R-4020F-S0012-ND. I found this encoder through another UBitX builder. They were ordered late last night and I expect them via USPS first class mail on Monday
Mike
On Fri, May 18, 2018, 3:57 PM kj6etl < pa1zz@...> wrote: I just bought these but I can feel clicks (steps) while turning. Does this mean they send me a part that isn't an EC11?
What else do I need to search for? I prefer a North American vendor for fast shipment.
This is what I just received.
|
Re: Winlink configuration with the uBitx
I use the usb for cat control and do not have too much trouble. Sure it raises the local receiver noise a small bit, but its not enough to worry about.
On Fri, May 18, 2018, 4:11 PM Gordon Gibby < ggibby@...> wrote:
Geewhiz, I don¡¯t think this is hard at all. ? I don¡¯t quite understand exactly what you¡¯re doing.? Get some sort of sound card interface, either a signal link or a homebrew,
Connect up the microphone connection to the Microbit X microphone.
Connect up the speaker connection to the MicroBit X speaker output.
Connect up the push to talk connection to the MicroBid ask push to talk.
Put ferrites on the microphone and speaker connection.
Connect the signal link or sound card to your computer.? Put ferrites on that connection also...
Start with relatively low power, you can set that by setting the transmit gain on the signal link fairly low. That will reduce your chance of having radio frequency interference.
Don¡¯t connect anything at all to the raduino USB interface.? It is a very vulnerable point for radio frequency interference.
At this point you should be able to do the WINLINK transmit level test without any problem.
Pick any legal frequency and initiate a call to any WINLINK station, don¡¯t try to connect yet, just make sure he can get through a series of calls without crashing.? You need to be in the CW/digital portion of the band
Finally, try to connect to WINLINK station. Remember they center frequency is 1.5 kHz up from the dial frequency. And they all use upper side band.
Where are you located? If you can connect to Florida, I can try to listen for your signal.
It always takes a bit to get this going but once you figure it out it¡¯s easy.
Cheers
Gordon
If I remember correctly, the arduino being reset usually is caused by the DTR of serial port. You might need to find a way to configure the serial chip to not use the DTR pin. I have been meaning to look into this as well, cause each time I
start up wsjt-x, the ubitx resets.
On Fri, May 18, 2018, 3:49 PM Josh Walton via Groups.Io <josh.walton76= [email protected]> wrote:
After scanning the message archives, and finding a good bit of Winlink references, but nothing helpful for setting up WInlink to work with the uBitx, I thought I'd post a direct question to the group.
How do you best interface and configure WInlink to work with the uBitx?
My current configuration has failed:
uBitx with the CEC firmware V 1.061
soundcard interface directly with the mic and speaker jack (worked well with FLDIGI)
USB connected to raduino
Winlink setup under radio setup:
Select Radio Model: Yaesu? FT 817
USB
PPT Port: COM12, Baud 38400
When I do this, the uBitx just keeps re-setting at each PPT attempt.
I've tried soldering a 100 ohm resistor as Ian Lee suggests on between the V4 and Reset pin, just no luck
Any suggestions from the group?
--
----------
N5WLF, Greggory (or my nickname, Ghericoan)
General Class, Digital Radio Hobbyist
--
----------
N5WLF, Greggory (or my nickname, Ghericoan)
General Class, Digital Radio Hobbyist
|
Thanks for the Reply Ashar - I hope your Dad is OK
Kevin K5KDT
|
Best wishes and prayers for your father!
Roy WA0YMH
On Fri, May 18, 2018, 1:59 PM Ashhar Farhan < farhanbox@...> wrote: The trouble is me. I am supposed to ship out an updated firmware. They are waiting for that. The boards are ready,the software was supposed to have been delivered last week, but dad had to undergo an surgery so it knocked a week off my sked. I haven't travelled to dayton either. Hopefully, I will use it whole of tomorrow and the board will start flying out by evening.
|
Re: Winlink configuration with the uBitx
Geewhiz, I don¡¯t think this is hard at all. ? I don¡¯t quite understand exactly what you¡¯re doing. ?Get some sort of sound card interface, either a signal link or a homebrew,
Connect up the microphone connection to the Microbit X microphone.
Connect up the speaker connection to the MicroBit X speaker output.
Connect up the push to talk connection to the MicroBid ask push to talk.
Put ferrites on the microphone and speaker connection.
Connect the signal link or sound card to your computer. ?Put ferrites on that connection also...
Start with relatively low power, you can set that by setting the transmit gain on the signal link fairly low. That will reduce your chance of having radio frequency interference.
Don¡¯t connect anything at all to the raduino USB interface. ?It is a very vulnerable point for radio frequency interference.
At this point you should be able to do the WINLINK transmit level test without any problem.
Pick any legal frequency and initiate a call to any WINLINK station, don¡¯t try to connect yet, just make sure he can get through a series of calls without crashing. ?You need to be in the CW/digital portion of the band
Finally, try to connect to WINLINK station. Remember they center frequency is 1.5 kHz up from the dial frequency. And they all use upper side band.
Where are you located? If you can connect to Florida, I can try to listen for your signal.
It always takes a bit to get this going but once you figure it out it¡¯s easy.
Cheers
Gordon
toggle quoted message
Show quoted text
If I remember correctly, the arduino being reset usually is caused by the DTR of serial port. You might need to find a way to configure the serial chip to not use the DTR pin. I have been meaning to look into this as well, cause each time I
start up wsjt-x, the ubitx resets.
On Fri, May 18, 2018, 3:49 PM Josh Walton via Groups.Io <josh.walton76= [email protected]> wrote:
After scanning the message archives, and finding a good bit of Winlink references, but nothing helpful for setting up WInlink to work with the uBitx, I thought I'd post a direct question to the group.
How do you best interface and configure WInlink to work with the uBitx?
My current configuration has failed:
uBitx with the CEC firmware V 1.061
soundcard interface directly with the mic and speaker jack (worked well with FLDIGI)
USB connected to raduino
Winlink setup under radio setup:
Select Radio Model: Yaesu? FT 817
USB
PPT Port: COM12, Baud 38400
When I do this, the uBitx just keeps re-setting at each PPT attempt.
I've tried soldering a 100 ohm resistor as Ian Lee suggests on between the V4 and Reset pin, just no luck
Any suggestions from the group?
--
----------
N5WLF, Greggory (or my nickname, Ghericoan)
General Class, Digital Radio Hobbyist
|
Re: Winlink configuration with the uBitx
If I remember correctly, the arduino being reset usually is caused by the DTR of serial port. You might need to find a way to configure the serial chip to not use the DTR pin. I have been meaning to look into this as well, cause each time I start up wsjt-x, the ubitx resets.
On Fri, May 18, 2018, 3:49 PM Josh Walton via Groups.Io <josh.walton76= [email protected]> wrote: After scanning the message archives, and finding a good bit of Winlink references, but nothing helpful for setting up WInlink to work with the uBitx, I thought I'd post a direct question to the group.
How do you best interface and configure WInlink to work with the uBitx?
My current configuration has failed:
uBitx with the CEC firmware V 1.061
soundcard interface directly with the mic and speaker jack (worked well with FLDIGI)
USB connected to raduino
Winlink setup under radio setup:
Select Radio Model: Yaesu? FT 817
USB
PPT Port: COM12, Baud 38400
When I do this, the uBitx just keeps re-setting at each PPT attempt.
I've tried soldering a 100 ohm resistor as Ian Lee suggests on between the V4 and Reset pin, just no luck
Any suggestions from the group?
--
----------
N5WLF, Greggory (or my nickname, Ghericoan)
General Class, Digital Radio Hobbyist
|
I just bought these but I can feel clicks (steps) while turning. Does this mean they send me a part that isn't an EC11?
What else do I need to search for? I prefer a North American vendor for fast shipment.
This is what I just received.
https://www.ebay.com/itm/US-Stock-5x-Rotary-Encoder-Switch-EC11-Audio-Digital-Potentiometer-Handle-20mm/371842294877?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
|
Winlink configuration with the uBitx
After scanning the message archives, and finding a good bit of Winlink references, but nothing helpful for setting up WInlink to work with the uBitx, I thought I'd post a direct question to the group.
How do you best interface and configure WInlink to work with the uBitx?
My current configuration has failed:
uBitx with the CEC firmware V 1.061
soundcard interface directly with the mic and speaker jack (worked well with FLDIGI)
USB connected to raduino
Winlink setup under radio setup:
Select Radio Model: Yaesu? FT 817
USB
PPT Port: COM12, Baud 38400
When I do this, the uBitx just keeps re-setting at each PPT attempt.
I've tried soldering a 100 ohm resistor as Ian Lee suggests on between the V4 and Reset pin, just no luck
Any suggestions from the group?
|
Thanks for the information ?Ashaar, hope your Dad is ok. I ordered my first one yesterday.
--
73's ?de kn4ud ?
Allen ?Merrell
|
atouk
Ghericoan
Skip Davis
kj6etl