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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Re: UbitX no RF out SSB and CW
Sorry for this, all, but just glimpsed this exchange:
Evan, have you ANY electrical knowledge at all? You seem to be too junior in Hamdom to realize that a Bitx of any sort requires that much background at least. But here goes:
Voltage is a relative measurement: difference between 2 points. If only one is quoted (Voltage On ...) The other point will be 0V - 'Ground'/'Earth', and that in modern parlace is the negative (-ve), and not always one particular color though usually black. This will apply to your meter leads - they will be black and red, the red being positive (+ve). Now try again. What do you measure?
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Re: Intermodulation Performance
Allison: ? So, then, are bandpass filters the only option? Are there in-band spurs? ? David A Posthuma, WD8PUO ?
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From: [email protected] <[email protected]> On Behalf Of ajparent1/KB1GMX
Sent: Wednesday, August 22, 2018 5:46 PM
To: [email protected]
Subject: Re: [BITX20] Intermodulation Performance ? David,
?Will low-pass filters not correct the spurs generated as well as harmonics? Thanks for sharing your wisdom.
No.? Often the spurs are below the cutoff of a low pass frequency , they are low in frequency so they get to pass.
They are their to suppress harmonic and spurs that occur above the cutoff frequency.? Important but half the
job in some cases.
Good looking filter.
Allison
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Re: UbitX no RF out SSB and CW
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.
On Wed, Aug 22, 2018 at 3:53 PM Jerry Gaffke via Groups.Io <jgaffke= [email protected]> wrote: Do you see 12v on the tabs of the two IRF510's?
You don't have to key the transmitter to see this,
just have the receiver running.
When you key the transmitter, the IRF510 gates rise up from ground to turn things on.
What is the gate voltage at each IRF510 when you key the transmitter?
You can make these measurements with a DC voltmeter.
See 12v on the tabs (drans) of the IRF510.
Something like 4v on the gates, but only when transmitting
Jerry
On Wed, Aug 22, 2018 at 03:30 PM, Evan Clark (OSC) wrote:
orry if the last bit of the previous post was phrased oddly. I have connected the brown wire on the power in to the red one, so I am getting 12v to the finals. I now have 12v between pins 1 and 2 as well as 2 and 3. I'm still not seeing even a budge on the power meter, though.
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Re: UbitX no RF out SSB and CW
Do you see 12v on the tabs of the two IRF510's?
You don't have to key the transmitter to see this,
just have the receiver running.
When you key the transmitter, the IRF510 gates rise up from ground to turn things on.
What is the gate voltage at each IRF510 when you key the transmitter?
You can make these measurements with a DC voltmeter.
See 12v on the tabs (drans) of the IRF510.
Something like 4v on the gates, but only when transmitting
Jerry
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On Wed, Aug 22, 2018 at 03:30 PM, Evan Clark (OSC) wrote:
orry if the last bit of the previous post was phrased oddly. I have connected the brown wire on the power in to the red one, so I am getting 12v to the finals. I now have 12v between pins 1 and 2 as well as 2 and 3. I'm still not seeing even a budge on the power meter, though.
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Re: UbitX no RF out SSB and CW
Sorry if the last bit of the previous post was phrased oddly. I have connected the brown wire on the power in to the red one, so I am getting 12v to the finals. I now have 12v between pins 1 and 2 as well as 2 and 3. I'm still not seeing even a budge on the power meter, though.
Ok I may be onto something. I removed the DC connector and opted for Anderson Power Poles for battery power usage. I did not do the proper research apparently (took 5 seconds to look at the wireup). In my swap, I connected the red to red and black to black. This left the brown wire (PA power) unconnected... not sure what my thought process was there. Anyways, I have not had 12 volts on the finals. Despite this, I still have 12 volts on the finals.
On Wed, Aug 22, 2018 at 2:26 PM Jerry Gaffke via Groups.Io <jgaffke= [email protected]> wrote: Do a thorough visual inspection of the power amp, everything from Q90 out to the antenna jack.
Including the antenna jack.
The toroids and hand wound and installed by hand.
A bad solder job due to enamel remaining on the magnet wire could do this, you could check for that with an ohmmeter.
Or a broken wire due to jostling when shipped
Try hooking a 50 ohm dummy load and wattmeter between T11 pin 5 and ground.
That way we go around the transmit low pass filters and the relays at KT1,2,3 that select one of the filters.
Jerry
On Wed, Aug 22, 2018 at 02:20 PM, Jerry Gaffke wrote:
I would not just randomly replace stuff.
You have dozens of parts to suspect.
And it worked when shipped.
Do you have 12v applied to the IRF510's when transmitting?
You should see 12v to ground on the tabs of the IRF510's when transmitting.
Could be as simple as not having 12v wired to the PA-PWR pin of that 3 pin uBitx connector as shown in the WireUp diagram on hfsignals.?
You should have a 50 ohm dummy load hooked up when testing the transmitter.
Output is typically 10 watts, but if you only use it for short periods at less than 50 percent of the time,
a 5 watt dummy load won't get too hot.
I doubt it will damage anything to test the transmitter without a dummy load, but it could.
Jerry
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Re: Intermodulation Performance
Iz oos,
Its rare that distortion is heard on frequency.
Is the guy 3khz up or down from you that would like to not hear you and you sputter and splatter.
So with the good radio listen to your audio then flip its sideband and listen for stuff likely unintelligable
and then move up or down and listen.??
Did this onece on 6M (deserted part of the band) to prove a point tto someone that?
felt it was great ausio even though he had the knobs set to 11 on the scale of 10.
My commercial 6M rig if I run the audio up the image on the SA gets wide yet no one
on frequency hears much other than, its louder.? If I add over driving the power amp
its the same!? However at the extreme tested on the air one time The band width
at 15db down was 60khz and yet the guy maybe 10 miles away was sounds great
and he even knows my voice from club meetings.
Good audio reports are very misleading about all the stuff their receiver is filtering out
but the other poor guy trying to share the band is not enjoying it.
Allison
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Re: UbitX no RF out SSB and CW
Ok I may be onto something. I removed the DC connector and opted for Anderson Power Poles for battery power usage. I did not do the proper research apparently (took 5 seconds to look at the wireup). In my swap, I connected the red to red and black to black. This left the brown wire (PA power) unconnected... not sure what my thought process was there. Anyways, I have not had 12 volts on the finals. Despite this, I still have 12 volts on the finals.
On Wed, Aug 22, 2018 at 2:26 PM Jerry Gaffke via Groups.Io <jgaffke= [email protected]> wrote: Do a thorough visual inspection of the power amp, everything from Q90 out to the antenna jack.
Including the antenna jack.
The toroids and hand wound and installed by hand.
A bad solder job due to enamel remaining on the magnet wire could do this, you could check for that with an ohmmeter.
Or a broken wire due to jostling when shipped
Try hooking a 50 ohm dummy load and wattmeter between T11 pin 5 and ground.
That way we go around the transmit low pass filters and the relays at KT1,2,3 that select one of the filters.
Jerry
On Wed, Aug 22, 2018 at 02:20 PM, Jerry Gaffke wrote:
I would not just randomly replace stuff.
You have dozens of parts to suspect.
And it worked when shipped.
Do you have 12v applied to the IRF510's when transmitting?
You should see 12v to ground on the tabs of the IRF510's when transmitting.
Could be as simple as not having 12v wired to the PA-PWR pin of that 3 pin uBitx connector as shown in the WireUp diagram on hfsignals.?
You should have a 50 ohm dummy load hooked up when testing the transmitter.
Output is typically 10 watts, but if you only use it for short periods at less than 50 percent of the time,
a 5 watt dummy load won't get too hot.
I doubt it will damage anything to test the transmitter without a dummy load, but it could.
Jerry
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Re: Intermodulation Performance
David,
?Will low-pass filters not correct the spurs generated as well as harmonics? Thanks for sharing your wisdom.
No.? Often the spurs are below the cutoff of a low pass frequency , they are low in frequency so they get to pass.
They are their to suppress harmonic and spurs that occur above the cutoff frequency.? Important but half the
job in some cases.
Good looking filter.
Allison
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Re: 80 meter bandpass filter
Yes ...Since the relays at input and output are released and need be operated to tie to final/antenna, I just tack soldered some short pigtails to SMB connectors thence to TR502/7L13
Jim
On Wed, Aug 22, 2018 at 12:12 PM, Kees T <windy10605@...> wrote: Jim,
Are you just sweeping the existing filter on the uBITX board ?
73 Kees K5BCQ?
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Re: UbitX no RF out SSB and CW
Do a thorough visual inspection of the power amp, everything from Q90 out to the antenna jack.
Including the antenna jack.
The toroids and hand wound and installed by hand.
A bad solder job due to enamel remaining on the magnet wire could do this, you could check for that with an ohmmeter.
Or a broken wire due to jostling when shipped
Try hooking a 50 ohm dummy load and wattmeter between T11 pin 5 and ground.
That way we go around the transmit low pass filters and the relays at KT1,2,3 that select one of the filters.
Jerry
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Show quoted text
On Wed, Aug 22, 2018 at 02:20 PM, Jerry Gaffke wrote:
I would not just randomly replace stuff.
You have dozens of parts to suspect.
And it worked when shipped.
Do you have 12v applied to the IRF510's when transmitting?
You should see 12v to ground on the tabs of the IRF510's when transmitting.
Could be as simple as not having 12v wired to the PA-PWR pin of that 3 pin uBitx connector as shown in the WireUp diagram on hfsignals.?
You should have a 50 ohm dummy load hooked up when testing the transmitter.
Output is typically 10 watts, but if you only use it for short periods at less than 50 percent of the time,
a 5 watt dummy load won't get too hot.
I doubt it will damage anything to test the transmitter without a dummy load, but it could.
Jerry
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Re: UbitX no RF out SSB and CW
I would not just randomly replace stuff.
You have dozens of parts to suspect.
And it worked when shipped.
Do you have 12v applied to the IRF510's when transmitting?
You should see 12v to ground on the tabs of the IRF510's when transmitting.
Could be as simple as not having 12v wired to the PA-PWR pin of that 3 pin uBitx connector as shown in the WireUp diagram on hfsignals.?
You should have a 50 ohm dummy load hooked up when testing the transmitter.
Output is typically 10 watts, but if you only use it for short periods at less than 50 percent of the time,
a 5 watt dummy load won't get too hot.
I doubt it will damage anything to test the transmitter without a dummy load, but it could.
Jerry
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Show quoted text
On Wed, Aug 22, 2018 at 02:06 PM, Evan Clark (OSC) wrote:
Jerry, thanks for the response! I have an Icom 740, which is unable to tune to 11.997 HMz, but I am able to pick up the CW tone transmitted from the ubitx when tuned to the same frequency. Good news! In addition, I am able to receive with the ubitx the tone when generated from the 740. So I must be TXing milliwatts? My first thought would be to replace the IRF510s.
toggle quoted message. . .
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Re: UbitX no RF out SSB and CW
Jerry, thanks for the response! I have an Icom 740, which is unable to tune to 11.997 HMz, but I am able to pick up the CW tone transmitted from the ubitx when tuned to the same frequency. Good news! In addition, I am able to receive with the ubitx the tone when generated from the 740. So I must be TXing milliwatts? My first thought would be to replace the IRF510s.
On Wed, Aug 22, 2018 at 1:46 PM Jerry Gaffke via Groups.Io <jgaffke= [email protected]> wrote: Since you can hear the sidetone, you have U1 working.
Some people have had trouble with the center pin of a coax BNC connector not connecting well
with the BNC socket provided with the kit.? ? Maybe go around that BNC socket somehow during initial tests,
or at least verify the center pin is making a good connection by using an ohmmeter.
?
Does the receiver work?
You will need maybe 60 feet of wire out the window for an antenna before it will hear much.
Do you have some other shortwave receiver around, preferably one capable of receiving SSB transmissions?
With the uBitx, does this other receiver hear a carrier at about 11.997mhz when placed near the uBitx?
You should hear that during both transmit and receive.
Does this other receiver hear attempts at transmitting CW into a dummy load when placed near the uBitx?
Does it hear SSB transmissions from the uBitx when placed near?
Could be that the transmitter is mostly working, but the final amplifier is not.
Jerry, KE7ER
On Wed, Aug 22, 2018 at 01:16 PM, Evan Clark (OSC) wrote:
Hi all,
?
I'm somewhat new but I've spent a lot of time looking on these forums for a solution to my issue. As a disclaimer, I started this project knowing almost nothing about electronics, save ohms law and the like.?
?
When I first got my ubitx I plugged it in WAY before I ever should have, ie before I was even halfway done. This blew my U1, or it shipped faulty, either way that has been replaced. Now I have it at a point where it should be working perfectly but, of course, it's not. Connected to a dummy load and power meter, I get 0 watts out when yelling into the mic, as well as when shorting the key jack to ground. With the mic, it switches into TX and I can hear the relay click. When in CW, I get the click, it's switches to CW, and I hear the side tone. Still, no power out.
?
I have a multimeter, but again I'm quite new to all this so use laymens terms if possible. Thanks!
?
-Evan Clark?
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Re: UbitX no RF out SSB and CW
Since you can hear the sidetone, you have U1 working.
Some people have had trouble with the center pin of a coax BNC connector not connecting well
with the BNC socket provided with the kit.? ? Maybe go around that BNC socket somehow during initial tests,
or at least verify the center pin is making a good connection by using an ohmmeter.
?
Does the receiver work?
You will need maybe 60 feet of wire out the window for an antenna before it will hear much.
Do you have some other shortwave receiver around, preferably one capable of receiving SSB transmissions?
With the uBitx, does this other receiver hear a carrier at about 11.997mhz when placed near the uBitx?
You should hear that during both transmit and receive.
Does this other receiver hear attempts at transmitting CW into a dummy load when placed near the uBitx?
Does it hear SSB transmissions from the uBitx when placed near?
Could be that the transmitter is mostly working, but the final amplifier is not.
Jerry, KE7ER
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On Wed, Aug 22, 2018 at 01:16 PM, Evan Clark (OSC) wrote:
Hi all,
?
I'm somewhat new but I've spent a lot of time looking on these forums for a solution to my issue. As a disclaimer, I started this project knowing almost nothing about electronics, save ohms law and the like.?
?
When I first got my ubitx I plugged it in WAY before I ever should have, ie before I was even halfway done. This blew my U1, or it shipped faulty, either way that has been replaced. Now I have it at a point where it should be working perfectly but, of course, it's not. Connected to a dummy load and power meter, I get 0 watts out when yelling into the mic, as well as when shorting the key jack to ground. With the mic, it switches into TX and I can hear the relay click. When in CW, I get the click, it's switches to CW, and I hear the side tone. Still, no power out.
?
I have a multimeter, but again I'm quite new to all this so use laymens terms if possible. Thanks!
?
-Evan Clark?
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Re: Intermodulation Performance
Kees, ? In no way am I questioning the strategies you and the team are working through. But can you educate me as to why uBitx doesn¡¯t just use programming to simply select the appropriate band-specific low-pass filter such as presented by this 9-band $34 kit at ? Will low-pass filters not correct the spurs generated as well as harmonics? Thanks for sharing your wisdom. ? 
? David A Posthuma, WD8PUO ?
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From: [email protected] <[email protected]> On Behalf Of Kees T
Sent: Wednesday, August 22, 2018 3:01 PM
To: [email protected]
Subject: Re: [BITX20] Intermodulation Performance ? Allen and David,
Right now this is just a test to see what the results look like and "if there is a pony in the room". We may just provide the Gerber files, the LPF Relay boards, A complete LPF upgrade kit (not sure I can handle the potential demand after the AGC/Click activity), or just give it to someone else to run with ...?
73 Kees K5BCQ
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Re: Intermodulation Performance
Iz
The primary problem caused by high IMD is splatter outside the bandpass of the sideband filter. This shows up on the opposite sideband and on the high (audio) frequency side of the desired sideband. We have all heard this when an overmodulated signal is parked 3 KHz away and we get "static crashes" in the 3 KHz that we are listening to. On a waterfall is shows up as a broadening of the base of the signal.
I don't think you will find the IMD products affecting the intelligibility of the audio even at the very high -12 dBc levels I measured. What did happen is the transmitted noise floor on the opposite sideband and outside the filter rose 20-30 dB over the the single tone level. If there is interest I can replicate that test and show what it looks like on the spectrum analyzer.
WA8TOD
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Re: Nextion 3.2 for CEC 1.097
#ubitx
Hi Darren, VE3XLT
Can you make this correction to? CEC 1.097 Nextion screen for my basic 3.5" display?
TA2FU Alper
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Re: Intermodulation Performance
I greatly appreciate your efforts and that of the rest of the team. ? David A Posthuma, WD8PUO 1 (616) 283-7703 ?
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From: [email protected] <[email protected]> On Behalf Of Kees T
Sent: Wednesday, August 22, 2018 3:01 PM
To: [email protected]
Subject: Re: [BITX20] Intermodulation Performance ? Allen and David,
Right now this is just a test to see what the results look like and "if there is a pony in the room". We may just provide the Gerber files, the LPF Relay boards, A complete LPF upgrade kit (not sure I can handle the potential demand after the AGC/Click activity), or just give it to someone else to run with ...?
73 Kees K5BCQ
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UbitX no RF out SSB and CW
Hi all,
I'm somewhat new but I've spent a lot of time looking on these forums for a solution to my issue. As a disclaimer, I started this project knowing almost nothing about electronics, save ohms law and the like.?
When I first got my ubitx I plugged it in WAY before I ever should have, ie before I was even halfway done. This blew my U1, or it shipped faulty, either way that has been replaced. Now I have it at a point where it should be working perfectly but, of course, it's not. Connected to a dummy load and power meter, I get 0 watts out when yelling into the mic, as well as when shorting the key jack to ground. With the mic, it switches into TX and I can hear the relay click. When in CW, I get the click, it's switches to CW, and I hear the side tone. Still, no power out.
I have a multimeter, but again I'm quite new to all this so use laymens terms if possible. Thanks!
-Evan Clark?
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Re: 80 meter bandpass filter
Jim, it sounded strange to me as well. But most qrps have just a final transistor and all the harmonics have to be filtered out. In the uBitx the push pull configuration of the PA attenuates the even harmonics so the corner can be shifted some Mhz allowing more bands to pass (eg.? 80 and 60m).
Il 20/ago/2018 23:46, "Jim Tibbits" < ab7vf1@...> ha scritto: Aha!!!! photo of "80 meter" bandpass filter on my ubitx ...L20, L21, L22 as swept? ..corner frequency is closer to 6 mhz than 4
Jim
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David Posthuma
TA2FU