Has anybody measured the actual phase noise of the uBitx?
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SI5351 with output xfrormers
I am looking for a ready built SI5351 board, with isolating transformers.
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If you haven't installed a cap on the output of the DSP audio filter I suggest doing so. Without it I had a lot of strange things going on with my audio as I believe that there is DC voltage present on the output that was messing with the audio amp.
Michael VE3WMB
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Re: Intermodulation Performance
Sarma
Thank you for the great suggestion. This design is not from me. It is the work of?Kees K5BCQ. I agree...... a very nice job and I look forward to testing it.
Warren - WA8TOD
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Re: Nextion 3.2 for CEC 1.097
#ubitx
Hi Darren, VE3XLT
Can you please make this correction to? CEC 1.097 Nextion screen for my basic 3.5" (tft) display?
TA2FU Alper?
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Re: Loud sound on first power-up
#ubitx
On key down it should well over 2A.
Il 23/ago/2018 08:16, < micah@...> ha scritto: Still working on this. Speaker and audio out jack are wired correctly. So's the pot. It's supposed to be 10K right?
I have both a paddle and straight key jack wired up according to
The overall box draws about 500ma upon power up (with loud buzz from the speaker). That seems a bit high. There's nothing going out the antenna jack. What's the nominal value?
When I depress a straight key (plugged in to the key jack, so bringing the KEYER line straight to ground) the buzzing either stops or pulsates, like the internal keyer is doing its thing. Current consumption goes over 1A and I am seeing power going out the antenna. So that's good, I guess. I measure 5 volts on the KEYER line when nothing's pressed, so the 4.7k pull-up is working.
Could it be RF getting loose and feeding into the audio front end?
My LCD appears blank on the top line, and a series of fully-filled-in rectangles on the bottom line, no matter how I twiddle the trimmer on the back of the Raduino. Is that indicative of some wider problem?
Thanks for your troubleshooting brainstorming thoughts. :)
73,
MIcah AJ6BD
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Re: Loud sound on first power-up
#ubitx
Still working on this. Speaker and audio out jack are wired correctly. So's the pot. It's supposed to be 10K right?
I have both a paddle and straight key jack wired up according to
https://ubitx.net/wiring-up-a-paddle-and-straight-key/
The overall box draws about 500ma upon power up (with loud buzz from the speaker). That seems a bit high. There's nothing going out the antenna jack. What's the nominal value?
When I depress a straight key (plugged in to the key jack, so bringing the KEYER line straight to ground) the buzzing either stops or pulsates, like the internal keyer is doing its thing. Current consumption goes over 1A and I am seeing power going out the antenna. So that's good, I guess. I measure 5 volts on the KEYER line when nothing's pressed, so the 4.7k pull-up is working.
Could it be RF getting loose and feeding into the audio front end?
My LCD appears blank on the top line, and a series of fully-filled-in rectangles on the bottom line, no matter how I twiddle the trimmer on the back of the Raduino. Is that indicative of some wider problem?
Thanks for your troubleshooting brainstorming thoughts. :)
73,
MIcah AJ6BD
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Re: Intermodulation Performance
Warren, ?Thanks for nice job. We never get these vertical type relays. The filter caps may be? 3? for each section, ? so that the user? could reach closer value of capacvcitor by a combination. regards ?sarma
?vu3zmv
On Wed, Aug 22, 2018 at 11:37 PM Warren Allgyer < allgyer@...> wrote: Hi Kees
I would be honored to test and record data, publish if you wish, any filters you would be willing to send. I would of course return them after testing is complete. If you would like to proceed please contact me privately for shipping info.?
Thank you Kees.?
WA8TOD
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Re: Intermodulation Performance
Allison: ? No, I have been around, just too busy to keep up with all the threads. I wish there was a ¡°Status¡± page that could keep everybody posted on progress. ? Thanks, ? David A Posthuma, WD8PUO ?
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From: [email protected] <[email protected]> On Behalf Of ajparent1/KB1GMX
Sent: Wednesday, August 22, 2018 10:25 PM
To: [email protected]
Subject: Re: [BITX20] Intermodulation Performance ? David,
You must have missed the last three months.... and a pair of very long threads!? ;)
To clean that up yes, band pass filters are the option or some very fancy combination of
high pass and low pass which results in the same pass band as a band pass.
Generally the in band spurs happen to be extremely weak and as such not a worry
other than being annoying on receive.
Allison
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On Wed, Aug 22, 2018 at 09:16 PM, ajparent1/KB1GMX wrote:
K1 talks to K3 for Rf path.
The 12VDC side of K1 is successfully telling K3 what to do.? If K3 is not listening and is stuck in receive, then the transmit RF from the PA will dead end in K3 and the PA transistors will get hot.? They are not getting hot, so I don't think K3 is sticky. Apologies if I did not make it clear that the 12VDC control signals from K1 all appear to be working correctly on TX and RX.
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Re: Intermodulation Performance
David,
You must have missed the last three months.... and a pair of very long threads!? ;)
To clean that up yes, band pass filters are the option or some very fancy combination of
high pass and low pass which results in the same pass band as a band pass.
Generally the in band spurs happen to be extremely weak and as such not a worry
other than being annoying on receive.
Allison
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K1 talks to K3 for Rf path.? Look at the schematic.
Allison
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It's funny, I have been working on getting my Laserbeam set up. Yesterday I wired it up pretty much the same (minus the extra components as they were not mentioned in the set up for the LB) But I have a DPDT for the power, and switching it into the circuit, and a SPST switch for the 1-4dB gain. The only difference was that he put it before the pot, not after like I had done. So... Today I put it before the pot. It's still not right though. When I switch it into the circuit it's like the audio gets sucked out of the thing. My LED indication is all wrong too. I have also noticed that since I put it in, I have a birdy farm. I am going to have to rethink how I have it, and where I have it. I have my uBitx in an extruded aluminum case, so I might raise the board up a couple levels and get the Laserbeam right next to the volume knob so there's very little wire between the ins and outs. Right now there's too much wire. But I also need to sort out why it's not working.?
When it's switched in, it's like the audio is no longer being amplified. If I switch in the +4 gain, It's just minimal audio. I have the LEDs set up on an RGB led, red being peak, Blue being Band width, and green being center freq.?
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Good Evening, All. My K1 relay was getting intermittently sticky on TX, so I decided to replace it.? I used an AXICOM with the same pinouts as the stock Hongfa.? I'm not very good at desoldering and tore up some of the pads on the board. A little finagling and everything on the DC side of the relay seems to be working. The connections labeled TX on the schematic are getting 12V, and the connections labeled RX are getting 12V when they're supposed to and 0V when they're not supposed to.
?
But it's not transmitting.? After studying the schematic for what might be a problem with the new relay install, I'm wondering what's the purpose of the RF side of K1?? It appears that when T/R is off, then the signal from the BNC connector center goes through K3 and through K1 to the first set of filters, and so on.? When T/R is high (5V from the Raduino signalling for transmitting), then K3 disconnects the received signal trace from the BNC connector.? K1 grounds the trace coming from K3.? Is this to prevent transmission RF energy from bleeding into C80, causing some potentially nasty feedback??
And what would this have to do with the rig not transmitting?? The antenna signal is getting into the receive section, because RX appears fine.? If I'd done something wrong and K1 wasn't interrupting the path from K3, then it should transmit anyway?
Am I missing something?
It's possible I damaged one of the delicate toroidal transformers I suppose.
Any ideas will be appreciated!
73,
Arvo
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Re: UbitX no RF out SSB and CW
Oh dran!
Any idea where the sparks came from?
Any obvious scorch marks?
Sounds like you bumped L8.
Look at the schematic, L8 feeds 12v from PA-PWR into the left side IRF510.
I have no idea what "bumped" means, but if you shorted the wire that L8 is wound with to ground somehow,
that will burn out the trace between L8 and PA-PWR.
It's possible you burnt the coil, does the wire look discolored?
Just holding the red voltmeter probe against L8 while the black probe is on ground would not do this,
because very little current would flow through the voltmeter..
With the power supply disconnected entirely, short the PA-PWR wire to ground
then short each IRF510 tab to ground.? This is to make sure any caps are discharged.
Then set the DVM to the lowest ohms scale and measure ohms from PA-PWR?
to each IRF510 tab in turn.? Both tabs should be close to zero ohms to PA-PWR.
If one reads a lot more than zero ohms then either the coil (L8 or L9) or the traces
got burned.
A scorched trace could be easily repaired by soldering down a piece of wire.
I doubt you blew the IRF510's or any other semiconductors.
The gates should not be zero volts when you are transmitting, should be about 4 volts.
ff they were zero volts when transmitting, then that was your original problem
Otherwise the rig was working.
Might be a good idea to lug it off to a local ham club,
explain your adventure to some of the others attending
see if somebody there is curious enough about the uBitx?
to look it over with you and show you the ropes.
Jerry
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On Wed, Aug 22, 2018 at 05:37 PM, Evan Clark (OSC) wrote:
Ok, crap. I WAS measuring 12v at the tabs and 0v at the gates. BUT I think I bumped the inductor in front of the left final. Puff of smoke, a few visable sparks. Now measuring .84 volts either tab. Feeling quite disheartened.
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Re: UbitX no RF out SSB and CW
Drain voltage dropped to 10 mv, now slowly increasing at 50mv
Ok, crap. I WAS measuring 12v at the tabs and 0v at the gates. BUT I think I bumped the inductor in front of the left final. Puff of smoke, a few visable sparks. Now measuring .84 volts either tab. Feeling quite disheartened.
On Wed, Aug 22, 2018 at 5:21 PM Dexter N Muir < dexy@...> wrote: I was thinking, Jerry, with Gate at 0V, Tab to either 0 or Gate would be 12V - *and* no RF out. :)
73 de ZL2DEX
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Re: UbitX no RF out SSB and CW
Ok, crap. I WAS measuring 12v at the tabs and 0v at the gates. BUT I think I bumped the inductor in front of the left final. Puff of smoke, a few visable sparks. Now measuring .84 volts either tab. Feeling quite disheartened.
On Wed, Aug 22, 2018 at 5:21 PM Dexter N Muir < dexy@...> wrote: I was thinking, Jerry, with Gate at 0V, Tab to either 0 or Gate would be 12V - *and* no RF out. :)
73 de ZL2DEX
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Re: UbitX no RF out SSB and CW
Dexter, welcome to the asylum.
A data sheet for the IRF510 would come in handy so you can identify source,gate and drain pins.? As Jerry stated, the tab is also connected to the drain, although he choose an 'alternate' spelling.
(Jerry is indeed a team player, 'there is no I in dran')
Best of luck with the uBITX,
Gary
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Re: UbitX no RF out SSB and CW
I was thinking, Jerry, with Gate at 0V, Tab to either 0 or Gate would be 12V - *and* no RF out. :)
73 de ZL2DEX
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Re: UbitX no RF out SSB and CW
Evan,
Not a stupid question.? All voltages are relative.??
In most cases, unless otherwise stated, relative to ground.
So black lead on ground, red lead on one of the gates.
Same goes for looking at the voltage on the IRF510 mounting tabs, that's relative to ground too.
If you see 12v on your meter both when looking at the IRF510 tabs and when looking at the IRF510 gates
relative to the +12 supply, that means they are probably both at 0 volts relative to ground.
And that's bad.
The IRF510 tabs should be 12v relative to ground whenever power is on.
Each gate should be about 4v above ground when the transmitter is keyed.
The gates can be? different, but should both be close to 4v.
Do not jump ahead and try adjusting the gate voltage without understanding the correct procedure.
Otherwise you almost certainly will blow the IRF510's due to excessive drain current.
Jerry
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On Wed, Aug 22, 2018 at 04:29 PM, Evan Clark (OSC) wrote:
Jerry, I'm still a little confused. When measuring the voltage on the gate for example, am I putting one end on the power input and one on the gate pin of the final? Sorry for such a noobish question. If that is the case, I'm reading 12 volts on the gate as well as the tabs.
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TA2FU
David Posthuma
Arvo W0VRA