? I have been lurking and trying to follow these treads and am getting real nervous.? ? I am elderly and not that proficient of a electronic tech,? don¡¯t have oscilloscopes, etc.??? I was told it was ready to work just needed to be assembled.???? Was I wrong? ? Am I in trouble here? ? I have about everything,? case, board, etc¡.???? but now am wondering if I should perhaps get someone younger (less shakey) and with more electronic and radio savvy to assemble it for me for a fee. ? ? I got this a couple months ago,? and think its possibly a bitx40 not a 20.?? Or basic ubitx.?? ? Any suggestions?? ? ? ? ?
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This tells me that there is a fault BEFORE the first mixer. High probability is a shorted
trifilar transformer. I found one such case by rocking the toroid and there was a jump
in SSB power.
Check the 45MHz L5 and L7 for bad connection. You can check for continuity with a
multimeter.
Most probably the fault is somewhere common to RX and RX.
Good luck, faults are usually very simple.
Raj
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At 27-10-18, Evan Clark (OSC) wrote: Thanks for the help everyone. I am now seeing over ten watts out when keying CW. Still need to fiddle with the SSB as I have no power out there. I also have some issues with the audio, I think that's just due to incorrect tune up but it seems way off. Thanks for everyone's help!
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Re: QSX 10W HF Linear PA kit
I use one that came with a Dremel. Small and handy.
I found the holes for the 0.6mm wire to be a tight fit. After making
bifilar
transformer the lead wires will not be straight and they struggle to
get through the kit pcb holes.
Hans can keep this in mind!
Half kit done, rest later!
Raj
At 26-10-18, you wrote:
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On Thu, Oct 25, 2018 at 11:21
PM, Glenn wrote:
another small issue..... all holes in the heat-sink have burs on
them.
You want to keep it FLAT as the devices have to be flat to it for best
heat transfer.
Burs are easily removed with a precision knife (Exacto or similar).?
A good builder
checks for accidental shorts prior to power up.
FYI the bigger thing is that the FBxx-2402 ferrite have sharp edges on
the holes
and can strip enamel from wires while winding.? I use a small cone
shaped
Carborundum stone to take the edges of the holes down.
Allison
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I hope you are not trying it with the K3 on the same bench.? You will fully overload (even the K3). it will give you wrong readings. - f
On Sat, Oct 27, 2018 at 2:26 AM Timothy Fidler < engstr@...> wrote: Forgot word to the wise? - TEF for what it is worth strongly advises against making Allard hardware mods with Original Farhan software/firmware in place. Or? ?you may go to hell in a hand basket with all sorts of issues? and? people like Maestro? Allard may have trouble working out where the hell you are. I Suggest you try to get out of current hole before you try to reflash the nano uP (if that is what you might think of next) .? People have been down that route and ended up with no tcvr at all (you really need a second Raduino to be sure you have a backout path).. ..or live dangerously.
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Ah, good to hear!
Jerry
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On Fri, Oct 26, 2018 at 04:29 PM, Evan Clark (OSC) wrote:
Thanks for the help everyone. I am now seeing over ten watts out when keying CW. Still need to fiddle with the SSB as I have no power out there. I also have some issues with the audio, I think that's just due to incorrect tune up but it seems way off. Thanks for everyone's help!
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Re: PA Alignment of uBITX
#ubitx
John
The key here is the 100 mA delta, per stage.
The receive current varies between minimum volume with no signal, and higher volume with a strong signal.
I sense you accomplished it okay.
Curt
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I'm not so concerned about the actual freqs but I would have thought that CLK2 would be the same freq on either USB or LSB for a given dial freq? but that doesn't seem to be the case. I'm trying to understand why that is. And what it should be.
And a small correction...I'm running CEC V1.11, not 1.01.
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Re: QSX 10W HF Linear PA kit
Hi, My package arrived from QRP Labs today. I was surprising how small these kits are. I thought they had only sent the amplifier until I looked much closer at the contents through the bubble wrap. QRP Labs seems to be well thought of so I believe these kits, I'm especially interested in the PA, will provide good design baselines for amplifier and filter projects. Tom, wb6b  --------  ?
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Re: QSX 10W HF Linear PA kit
Allison,
I bring the points up, so others less skilled then yourself or other experienced builders, can be aware of them when building the Amp, as they are not mentioned in the instructions.
I¡¯m not doubting the value of the Kit, I think it¡¯s excellent.
Glenn
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Thanks for the help everyone. I am now seeing over ten watts out when keying CW. Still need to fiddle with the SSB as I have no power out there. I also have some issues with the audio, I think that's just due to incorrect tune up but it seems way off. Thanks for everyone's help!
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¡°¡±Command an output freq equal to the stated crystal freq¡±¡±
Was what it was supposed to say. Sorry, missed that Siri error...
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On Oct 26, 2018, at 19:16, Gordon Gibby <ggibby@...> wrote:
I don¡¯t know, but the easiest way is simply to come in and output equal to the stated Krystal frequency and then adjust the crystal freq constant in the software to actual value . Mine typically were off by three or 4 kHz.
Correct the crystal frequency Constant in the software appropriately to represent reality, and then every frequency they create becomes perfect.
On Oct 26, 2018, at 19:03, Mark M <junquemaile@...> wrote:
As part of my endeavor to calibrate my uBitX V3 running the CEC 1.01 firmware, I was measuring the raduino clock frequencies with my frequency counter. My thought was to tweak the master clock via the Configuration Manager so that CLK2 is exactly 55 MHz when tuned to 10 Mhz. I was able to do that with USB selected but when I switched to LSB I was surprised to see CLK2 drop by about 6 kHz. I thought that CLK2 would be the dial freq plus 45 regardless of which sideband was selected, and that USB/LSB was determined by CLK1.
Clocks 0 and 1 appear to behave as expected.
What am I not understanding here?
Mark AA7TA
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I don¡¯t know, but the easiest way is simply to come in and output equal to the stated Krystal frequency and then adjust the crystal freq constant in the software to actual value . Mine typically were off by three or 4 kHz.
Correct the crystal frequency Constant in the software appropriately to represent reality, and then every frequency they create becomes perfect.
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On Oct 26, 2018, at 19:03, Mark M <junquemaile@...> wrote:
As part of my endeavor to calibrate my uBitX V3 running the CEC 1.01 firmware, I was measuring the raduino clock frequencies with my frequency counter. My thought was to tweak the master clock via the Configuration Manager so that CLK2 is exactly 55 MHz when tuned to 10 Mhz. I was able to do that with USB selected but when I switched to LSB I was surprised to see CLK2 drop by about 6 kHz. I thought that CLK2 would be the dial freq plus 45 regardless of which sideband was selected, and that USB/LSB was determined by CLK1.
Clocks 0 and 1 appear to behave as expected.
What am I not understanding here?
Mark AA7TA
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As part of my endeavor to calibrate my uBitX V3 running the CEC 1.01 firmware, I was measuring the raduino clock frequencies with my frequency counter. My thought was to tweak the master clock via the Configuration Manager so that CLK2 is exactly 55 MHz when tuned to 10 Mhz. I was able to do that with USB selected but when I switched to LSB I was surprised to see CLK2 drop by about 6 kHz. I thought that CLK2 would be the dial freq plus 45 regardless of which sideband was selected, and that USB/LSB was determined by CLK1.
Clocks 0 and 1 appear to behave as expected.
What am I not understanding here?
Mark AA7TA
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Forgot word to the wise? - TEF for what it is worth strongly advises against making Allard hardware mods with Original Farhan software/firmware in place. Or? ?you may go to hell in a hand basket with all sorts of issues? and? people like Maestro? Allard may have trouble working out where the hell you are. I Suggest you try to get out of current hole before you try to reflash the nano uP (if that is what you might think of next) .? People have been down that route and ended up with no tcvr at all (you really need a second Raduino to be sure you have a backout path).. ..or live dangerously.
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MT did you try my suggestion to install the NBR 12 xtal ..the highest of the complete set to try to pull the BFO up and get the USB out of the way ?? IF not , You have a socket , suggest you try it - given .? ?Also have you used the variable capacitor at the BFO to the same end ? Remember too that when you did the change out you now have a set of capacitors that are NOT calculated for you xtal set in the Cohn filter.? It may be fine but it is all in the reason of should be.? Finally to avoid changing out the cheap and nasty L in the BFO set (it looks too small to be of much use (I suspect the intent is to set the BFO wrt filter by xtal selection primarily) - finally you could use the next lower xtal set (that you made up by freq measurement - not shown on this post - ) to install as a pair in //el in your socket? to make up a super Vxo which is much more pullable using the LC set and you can go upp up and away.. up the ladder of success (like Don Draper/Dick Whitman? in the Lift ). MMen ;? Love it.?
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Re: PA Alignment of uBITX
#ubitx
Thanks Curt, Ok.?
That is step 1 and it feels like now I am putting out some power (rather than previously my dummy load didn't even warm up).
Trying now to understand the BFO setup - I think that is not setup correctly as I just hear "clicking in the audio".
John
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Allison's right, I screwed up on my last post.
That post was thinking it was a Bitx40, not a uBitx.
Ignore my last post.
Unless somebody else jumps in first, I'll try to rewrite that post
once I have some free time again.
Jerry, KE7ER
On Fri, Oct 26, 2018 at 11:34 AM, ajparent1/KB1GMX wrote:
Is this a bitx40 or a uBitx???? They are very different and I keep seeing references to both!
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On Fri, Oct 26, 2018 at 10:37 AM, Michael Trager wrote:
Anyone know what the purpose of the blue pot on the Raduino...contrast ?
Yes, contrast.
Distorted in what way, tones and pitch are off or voices only squeeky or bassy?
Elaborate?
Its not a DDS it is a NCO (Numerically Controlled Oscillator, a fancy PLL) and the
normal output is square wave.
if PTT changes frequency you have a wiring error or grounding issue.
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On Fri, Oct 26, 2018 at 11:22 AM, Jerry Gaffke wrote:
With the PTT switch pressed, measure the following voltages:
? ? TX? ? (should be +12v)
? ? U3 pin 1? ?(should be +5v)? ?Could alternately be measured at RV1 or C150
? ? R150? ? (both sides the same and same as the IRF510 gate, should vary between 0v and 5v as you turn RV1).
All of the voltages above are DC, measured with the black probe on ground a
Is this a bitx40 or a uBitx???? They are very different and I keep seeing references to both!
++++++++++++++++++++++++++++++++++++? uBitx only!++++++++++++++++
for ubitx U2 is the 5V source for get bias.? RV2 and RV3 are the bias adjust for each IRF510.
Note no audio into the mic or use a jumper to connect PTT to ground for SSB TX.
To dial in the bias urn the pots RV2 and 3 down to 0V on the gate (oddly its clockwise!).
Measure the radio current, whatever that is adjust RV2 for 100mA more.? The resulting
current is noted and then adjust RV3 for an additional 100ma.? Total current will be about
350mA give or take depending on the starting number.
With 12V on the drains the gates should be at 3-4V and about the same voltage for each
IRF510.
IF the gates are still at zero volts then you have other issues with burned traces.
That being done RV1 set to about 10 o-clock position (2/3 power) (its also backward)
as max power out is anti-clockwise.? Now you should see some power out.
Allison
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I suggest you pull the two pin PA-PWR1? connector from your Bitx40
while debugging this gate voltage issue.
With no 12v power to the IRF510 drains, minor explosions are much less likely.
You will only see a DC voltage on the IRF510 gate when transmitting, with the PTT switch closed.
The PTT switch grounds the bottom of the coil at relay K1, turning K1 on.
With K1 on, we have the +12v on K1 pin 5 connected to the TX node on K1 pin 1.
The +12v on TX goes into pin 3 of the LM78L05 regulator at U3, which should now provide +5v on pin 1.
The 10k pot at RV1 can be adjusted to provide any voltage between 0v and 5v at RV1 pin 2, we will adjust
it eventually to be roughly 4v.
Note that RV1 pin 2 is not connected to the LM78L05 at U3, it is just that the schematic is poorly drawn,
instead that RV1 pin 2 node goes down the schematic to the 47 ohm resistor at R150.
Since there is no DC load of any sort on the bottom of R150, the bottom (which is connected to the IRF510 gate)
should be at the same voltage as the top of R150.? So varies between 0 and 5v as you turn RV1.
With the PTT switch pressed, measure the following voltages:
? ? TX? ? (should be +12v)
? ? U3 pin 1? ?(should be +5v)? ?Could alternately be measured at RV1 or C150
? ? R150? ? (both sides the same and same as the IRF510 gate, should vary between 0v and 5v as you turn RV1).
All of the voltages above are DC, measured with the black probe on ground and the red probe on the signal of interest.
Your voltmeter should be set to perhaps 20 volts max, higher than your power supply voltage.
Make sure the meter is configured to measure voltage and not Amps.
If you get the IRF510 gate voltage to vary with RV1, then turn RV1 fully clockwise for minimum gate voltage.
This the opposite direction for minimum of most pots.
Now change your meter from volts to measure amps instead (at least 1 Amp max), and connect it in series with your power supply +12v wire
that goes into the Bitx40.? With the power supply off, reconnect the PA-PWR1? two pin connector to the Bitx40 board.
Put a 10W (or more) 50 ohm dummy load on the antenna port of the Bitx40.?
(You do have a dummy load, don't you?? If not, I'd recommend four Xicon 200 ohm 3W in parallel, Mouser?283-200-RC.)
Get some safety glasses on, as those IRF510's can explode, blowing out molten metal.
Cross your fingers and power up the supply.
I don't remember exactly what the current draw from your supply should be for a Bitx40, but believe it is around 150 ma.
Now ***very*carefully*** turn RV1 counterclockwise until that that initial power supply current increases by 100 ma (to about 250ma total).
I assume you are in SSB mode (not CW), and? do not have audio into the mike.
At first, turning RV1 won't have any effect, but a bit beyond halfway the current draw will suddenly increase rapidy as you turn.
Turn RV1 too far and you may find out why I recommend safety glasses.
When operating with audio into the mike, the Bitx40 might draw a couple amps from the power supply.
Someone attempting to fix a Bitx40 power amp? that is unsure how to use a voltmeter
is definitely jumping into the deep end of the pool.
If any of the above is confusing, I suggest you check in with a local ham club,?
see if anybody there is willing to help you sort this out.
Bring your Bitx40, schematic, PTT switch, power supply, dummy load, meter, and this post.
They may be able to get you going in the right direction in a few minutes.
?
Jerry
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On Fri, Oct 26, 2018 at 01:10 AM, Evan Clark (OSC) wrote:
I've messed up this ubitx a lot. Learning as I go... I guess. Today I pulled it out again to give it another shot, and found the burnt trace that caused me to put it away 2 months ago. That wasn't even the original issue with it, so I knew I had to find the other one. I have 12 volts on the tabs of the irf510s, but none on the gates while TXing. IIRC there should be around 4 volts there. Somehow while testing voltages between ground and the IRFs I burned another trace (between PA PWR and L8). Luckily this one was far easier to fix.?
Prior to burning the traces, I came here trying to solve the issue. Here's the link to that thread if it helps at all:?/g/BITX20/topic/24923512?p=,,,20,0,0,0::relevance,,No+RF+out+SSB,20,2,0,24923512,ct=1&ct=1
No idea what the problem is, I've been at this for over 6 months now, on and off of course. Any help figuring this out is much appreciated. Thanks!
-Evan
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Raj vu2zap