Rogier,
Thanks for sharing your progress.? Best of luck on the swap out.?
Have a fun weekend.
Gary
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Re: who is going to be the first to have a water cooled BITX? - warning time waster
On Fri, May 18, 2018 at 03:10 pm, ajparent1/KB1GMX wrote:
Doable.? And I'm not laughing.? ;)
I was clear I was 51% serious!?? I spent too much time at looking at my aquarium instead of being productive this afternoon.? It was a coin toss between posting about water cooling or putting the whole thing in a clear enclosure filled with mineral oil.? The water cooling seemed more extreme even if it does remind me friends I had in school that put $1500 stereos into $500 cars. ? --
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Re: who is going to be the first to have a water cooled BITX? - warning time waster
Liquid nitrogen is cheap and accessible.
Very fun to play with.
And you don't have to feel guilty as it dissipates back into the air from which it came.
Be sure to read up on first aid for frostbite.
Jerry, KE7ER
toggle quoted message
Show quoted text
On Fri, May 18, 2018 at 03:10 pm, ajparent1/KB1GMX wrote:
Doable.? And I'm not laughing.? ;)
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Seconded! and 90% of all electrical/electronic faults are at root actually mechanical!
73 all
ZL2DEX
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Wow, thanks for all the hard work figuring this issue out. I'll pull the Raduino off the main board and power it up with a micro USB connector later tonight and check to see if it reads 5 volts across the pins that you indicated.
I believe I have a new Nano Arduino in the box somewhere but if I need to replace it I think I will order new as you did and if that is the case I'll drop you a note asking how to contact India so as to order the new Raduino.
Thanks again, you may have saved me a ton of hair pulling on a head that went bald 15 years ago.?
Best wishes,?
Mike
On Fri, May 18, 2018, 5:55 PM kj6etl < pa1zz@...> wrote: I have almost the exact same issue with my uBitx!!!!
I spend many hours trying to diagnose this problem at the end you can narrow it down to this:
- Disconnect the raduino board from the main board
- Disconnect the main connector
- Power it with a USB cable
- Measure voltage between pin 4 and 6 (Yellow to Red)
- It should read 5 Volt
It it doesn't read 5 Volt your Raduino board is bad and you have to replace it. So I ordered a new one ($35 shipping from India shigh..). Meantime bought a generic and will attempt to replace the failed one. Who knows I might have it working before the orignal board arrives.
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Re: who is going to be the first to have a water cooled BITX? - warning time waster
Doable.? And I'm not laughing.? ;)
That might eclipse the hack of 30++ years ago.? 2n2219 in a block of aluminum with feedthoughs
and the cavity filled with transformer oil.? Got the thing to put out 10W with 30% duty cycle?
at 40mhz with that block anchored to a 6x6x2 inch heatsink.??
Its a matter of getting the heat out.? water works well.? People used to take 3CX100 (2c39)
and pull the air radiator and solder on a cap with hoses, distilled water is a good insulator
and with about 1000V you can push that poor 100W tube to nearly past 500W at UHF!?
For Bitx the real problem is the IRF510 thermal interface.? Once the die is dissipating
about 43W you have maxed out as you can't no matter what get the heat out due to
the TO220 thermal resistance 3.5 degrees C/watt so at 43W its going to be at
150.5C die temp.? ?At 150C it reverts back to sand.? Cooling the epoxy side is
ineffective.? Now if IR put that die on a flange with a heavy bond in(gate) and
out(drain) it has a chance.? ? On the bright side two push-pull would be doing
about 90W out (assuming 50% efficiency, doable at 40M).? My own testing got
to 85 when they expired.? ? However any effort to keep them cool is still a good thing.
RD16HHF is only hair better at 2.2 degrees C/W.? However there are other limitng factors.
If there is a quest for power then devices that can get rid of the heat are a must.
Selected properly and run conservatively they can be near indestructible.? Problem
is they are not cheap.
Allison
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Hi Gary,
Thanks for sharig yoru experience.
I was able connect to the Raduino and load software. But it still did not fix the problem I even ended up resolding the board thinking that there might be a cold weld causing the missing voltage.
This morning I received a and was able to load the software. I noticed a mayor differece in the fact that the led's on the Arduino are acrive whil on the failed Raduino there is only one sad led.
Meantime I ordered a new Raduino board from Farhan. Meantimme I am going to try to recplace the current one with this generic one, wish me luck...!
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This might help :-) 
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Thanks Tim, for the reply.
It is sealed and the size of a dime. If a replacement and extra extras were not coming in the mail and arriving Monday I would try to open her up but I'll wait and assemble the BitX40 as I wait.?
I may give the BitX40's 10K potentiometer running method a go on the UBitX as I wait. It should work on the band the radio is stuck on because of presumably a defective encoder.
Thanks Mike
On Fri, May 18, 2018, 4:38 PM Tim Gorman < tgorman2@...> 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
>
--
tim ab0wr
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Anyone a part number or description what to look for to get the same as shipped with the uBitx?
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Hi Skip,
Thanks for the reply.?
I described what it should be doing. The point is- It is not behaving as I described? and that is why I removed the encoder and ordered a replacement plus 4 spares. Mike
On Fri, May 18, 2018, 4:27 PM Skip Davis via Groups.Io <skipnc9o= [email protected]> wrote: 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. 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 have almost the exact same issue with my uBitx!!!! I spend many hours trying to diagnose this problem at the end you can narrow it down to this:
- Disconnect the raduino board from the main board
- Disconnect the main connector
- Power it with a USB cable
- Measure voltage between pin 4 and 6 (Yellow to Red)
- It should read 5 Volt
It it doesn't read 5 Volt your Raduino board is bad and you have to replace it. So I ordered a new one ($35 shipping from India shigh..). Meantime bought a generic and will attempt to replace the failed one. Who knows I might have it working before the orignal board arrives.
|
Re: who is going to be the first to have a water cooled BITX? - warning time waster
wouldn't vodka be better than water for cooling?
On Friday, May 18, 2018 2:14 PM, Doug W <dougwilner@...> wrote:
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.
--
|
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
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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
|
kj6etl
atouk
Ghericoan