开云体育

Excessive Noise

[email protected] All Messages By This Member #32583 Hey yall, I've built my boards and have them all hooked up.? I've started with receiver checkout, and unlike my V11 which was amazing !, I have a lot of noise, specially on 40M.? I'm not in an ideal environment yet, but the behavior is so different than V11.? I can pick up very strong CW signals (one!) and a spanish AM broadcast at 7.35 something.? So in the process of checking things out, I hooked up my SA to TX out on the RF board and TXed SSB, which looked fine.? Then I switched to CW, and the freq was good but when I released the key and the RX returned, I got this.? 25MHZ, and 3x, probably higher harmonics too.? Square wave!? These pop up after the first time I key the TX and remain. I'm running V50.2, metal chassis.? This appears in slightly different forms forms all bands, 160M-6M, but the spurs always appear at 25MHz .... I have other integration issues I have to resolve in the mean time, but what's up with this? Thanks Mark KU3O noiseTest.png
K9HZ All Messages By This Member #32585 开云体育 Mark, just remember, for troubleshooting… all you need is the Main board, the RF board, and the display… you can take everything else out of the chain (eg RX antenna straight to the RF-in on the RF board… and TX antenna or dummy load on the TX OUT of the RF board.?? ? Once calibrated, I do recommend removing JP4 from the RF board… no need for it being there except for calibration. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? toggle quoted message Show quoted text From: [email protected] <[email protected]> On Behalf Of epif18 via groups.io Sent: Wednesday, February 5, 2025 9:36 AM To: [email protected] Subject: [SoftwareControlledHamRadio] Excessive Noise ? Hey yall, I've built my boards and have them all hooked up.? I've started with receiver checkout, and unlike my V11 which was amazing !, I have a lot of noise, specially on 40M.? I'm not in an ideal environment yet, but the behavior is so different than V11.? I can pick up very strong CW signals (one!) and a spanish AM broadcast at 7.35 something.? So in the process of checking things out, I hooked up my SA to TX out on the RF board and TXed SSB, which looked fine.? Then I switched to CW, and the freq was good but when I released the key and the RX returned, I got this.? 25MHZ, and 3x, probably higher harmonics too.? Square wave!? These pop up after the first time I key the TX and remain. I'm running V50.2, metal chassis.? This appears in slightly different forms forms all bands, 160M-6M, but the spurs always appear at 25MHz .... I have other integration issues I have to resolve in the mean time, but what's up with this? Thanks Mark KU3O
Albert Peter All Messages By This Member #32593 Hi Mark, V12 hardware has lots more gain than V11. You may need to reduce the RF Gain to -10 or -15db. See if that helps. Al AC8GY
[email protected] All Messages By This Member #32601 Thanks Al. I'll give that a try and let you know.? Mark toggle quoted message Show quoted text On 02/06/2025 9:51 AM EST Albert Peter via groups.io <albertfpeter@...> wrote: ? ? Hi Mark, V12 hardware has lots more gain than V11. You may need to reduce the RF Gain to -10 or -15db. See if that helps. Al AC8GY
Tim All Messages By This Member #32633 Mark did that help I am trying to calibrate and all I see on spectrum scope is noise Changing frequency does not change spectrum or water fall. Tim?
[email protected] All Messages By This Member #32636 Hey Tim, Not yet.? I was tracing all the paths on the LPF control board to make sure I didn't have a problem with one of those 0179's.? I found a problem with the SWR xfmr in the tx path, so I fixed that, it had cut off rf output to 20W PA.? I put my nanoVNA on the antenna and got a good result on both RX and TX to and from RF board connections.? This was with everything installed.? This made the pulsating audio much better too.? When I pump several mV I/Q into the RX input on main, I get a good signal but the noise is still there.? I had replaced the ADC and resoldered all the SMA's on MAIN but no change.? Main is not generating noise as the noise goes away when I pull the RX I/Q in cable (silly, but I'm looking for the noise source). So what I saw was that raising the RF gain raises everything and increasing RX attenuation reduces everything.? I did do an RX CAL as recommended but no change.? I still need to look into that a little more. I have a single point ground, so I don't think there's a problem there.? I haven't hooked up a sig gen with a bunch of attenuators to see what the sensitivity really is. I need to get out of the basement and hook up to a full up antenna (in the garage!) and a good ground.? I could easily pick up W1AW on 40M in the basement with my V11 so I'm determined to get this figured out for the V12.? I don't have a cover on my case yet (metal chassis) but I have a hard time believing that noise is getting in given that all the connections are shielded.? I saw some traffic about noise coming from the display, but I waved my hand in there and there was no change in any signal. I need to rearrange my board positions which would shorten the power lines, coaxes and the BANDS cable. Hope is not a plan, but I'm hopin'. Mark KU3O
K9HZ All Messages By This Member #32637 开云体育 Mark…. You can unplug everything except the MAIN and RF boards (and the front panel and encoders) and the radio should work by just placing a receive antenna on the RX IN on the RF board.? If you still hear the moise, obviously its contained to the MAIN, RF, Front Panel, and power supply. ? That’s the way I always trouble shoot my V12 radios… strip them down to the basics.?? I have 6 of them sitting in various states of together-ness… most for experimentation. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? toggle quoted message Show quoted text From: [email protected] <[email protected]> On Behalf Of epif18 via groups.io Sent: Saturday, February 8, 2025 9:28 PM To: [email protected] Subject: Re: [SoftwareControlledHamRadio] Excessive Noise ? Hey Tim, Not yet.? I was tracing all the paths on the LPF control board to make sure I didn't have a problem with one of those 0179's.? I found a problem with the SWR xfmr in the tx path, so I fixed that, it had cut off rf output to 20W PA.? I put my nanoVNA on the antenna and got a good result on both RX and TX to and from RF board connections.? This was with everything installed.? This made the pulsating audio much better too.? When I pump several mV I/Q into the RX input on main, I get a good signal but the noise is still there.? I had replaced the ADC and resoldered all the SMA's on MAIN but no change.? Main is not generating noise as the noise goes away when I pull the RX I/Q in cable (silly, but I'm looking for the noise source). So what I saw was that raising the RF gain raises everything and increasing RX attenuation reduces everything.? I did do an RX CAL as recommended but no change.? I still need to look into that a little more. I have a single point ground, so I don't think there's a problem there.? I haven't hooked up a sig gen with a bunch of attenuators to see what the sensitivity really is. I need to get out of the basement and hook up to a full up antenna (in the garage!) and a good ground.? I could easily pick up W1AW on 40M in the basement with my V11 so I'm determined to get this figured out for the V12.? I don't have a cover on my case yet (metal chassis) but I have a hard time believing that noise is getting in given that all the connections are shielded.? I saw some traffic about noise coming from the display, but I waved my hand in there and there was no change in any signal. I need to rearrange my board positions which would shorten the power lines, coaxes and the BANDS cable. Hope is not a plan, but I'm hopin'. Mark KU3O
[email protected] All Messages By This Member #32638 Thanks Bill, that sounds like a plan.? I just finished hooking up my sig gen to one of the antenna with an output of -40dbm and 60dbm of attenuation, 7MHz AM, RF gain set at 0 and I could see and hear the signal (faint).? So right now, I have a sensitivity of -100dbm.? I do want to hook up my old linear power supply to see if I have switcher noise too.? Just out of curiosity, if you have ever found noise in Main or RF, what do you think the cause may be? Thanks again, Mark KU3O
[email protected] All Messages By This Member #32639 Should be 60db of attenuation
K9HZ All Messages By This Member #32640 开云体育 I’ve never had noise from an on-board source, but that doesn’t mean it couldn’t happen.? There is probably a solder bridge somewhere that is causing this… but keep it simple… to hone in on the area of the circuitry with the issue.? Oliver had some good input… if the clocks both look good… you can follow a calibrated input into the receiver front end… past the transformer (TP4), then past the attenuator and the gain stage (TP6)… if all that works there is only the mixer U1 and the filters at TP5 and TP3. ? Here is another great diagnostic tool that a lot of people forget about.?? You can take the RX I/Q output at J1 into your computer through the stereo input… load a SDR program like SDR Console and demodulate the signals as if it were the Main board.? [Note: this also means that with the addition of a simple software subroutine/ control module to the suite of existing provided modules in any of the SDR PC programs, anyone could build only the RF board and have a fully functional QRP Transceiver.? Other boards could be added to additional functionality]. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? toggle quoted message Show quoted text From: [email protected] <[email protected]> On Behalf Of epif18 via groups.io Sent: Sunday, February 9, 2025 9:43 AM To: [email protected] Subject: Re: [SoftwareControlledHamRadio] Excessive Noise ? Thanks Bill, that sounds like a plan.? I just finished hooking up my sig gen to one of the antenna with an output of -40dbm and 60dbm of attenuation, 7MHz AM, RF gain set at 0 and I could see and hear the signal (faint).? So right now, I have a sensitivity of -100dbm.? I do want to hook up my old linear power supply to see if I have switcher noise too.? Just out of curiosity, if you have ever found noise in Main or RF, what do you think the cause may be? Thanks again, Mark KU3O
[email protected] All Messages By This Member #32738 Hey yall' I think I found a player in the noise problem (maybe one of several!).? I had a very marginal power return connection that I corrected, not sure how this thing even worked with this problem.? Noise problem better but I have this pulsating audio problem that varies by band.? I'm running V12, Ver50.2, Debug off, TXCO, 528MHz, Faster with LTO.? 20M is the worst. I get the same problem going thru an audio amp or directly to MAIN with headphones.? I've tried different Teensy frequencies and all the LTO options to no avail.? I've looked thru the pulsating audio thread but they seemed to apply to older SW versions, maybe even V11 HW. Thoughts? Thanks Mark KU3O
[email protected] All Messages By This Member #32851 Hey yall' I've tried everything I can think of.? The pulsating noise corresponds to the sclk signal (pin 13 led which also pulsates) which seems to be modulated by the spectrum update rate that is then getting onto the power lines.? It's on the 12v,? 3.3v and 5v lines. Pulsating level and rate varies by band, particularly 20M. This pulsating happens with a full up system and with only MAIN and the display running (happens without the display hooked up too). I've rebuilt the power supplies on main, encased the display in copper, wrapped the rebuilt display cable in copper and grounded one end, retouched most of the solder joints, all to no avail.? I've changed the teensy and looked at the whole card under the microscope and nothing!? I'm using a metal case, single point ground, nothing is grounded to the case.? Using 50.2. So I need a MAIN circuit card.? Are card sets still available?? Does anyone have a V12 set they want to sell or an extra MAIN they want to get rid of?? Everything else works great, BPF, LPF, RF including the attenuators (which surprised me!). Thanks Mark KU3O
K9HZ All Messages By This Member #32853 开云体育 Mark… I’m fully restocked with T41 boards… latest revisions too.? I have at least 100 of each board gearing up for Hamvention. ? Unplug the RF board so its just the MAIN board and see if it still happens (maybe you already did this experiment).? If it’s still there, it has to be either the A/D, the D/A or the Audio hat.? They are the only things on the main board that are associated with the I2C Clock. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? toggle quoted message Show quoted text From: [email protected] <[email protected]> On Behalf Of epif18 via groups.io Sent: Friday, February 21, 2025 11:55 AM To: [email protected] Subject: Re: [SoftwareControlledHamRadio] Excessive Noise ? Hey yall' I've tried everything I can think of.? The pulsating noise corresponds to the sclk signal (pin 13 led which also pulsates) which seems to be modulated by the spectrum update rate that is then getting onto the power lines.? It's on the 12v,? 3.3v and 5v lines. Pulsating level and rate varies by band, particularly 20M. This pulsating happens with a full up system and with only MAIN and the display running (happens without the display hooked up too). I've rebuilt the power supplies on main, encased the display in copper, wrapped the rebuilt display cable in copper and grounded one end, retouched most of the solder joints, all to no avail.? I've changed the teensy and looked at the whole card under the microscope and nothing!? I'm using a metal case, single point ground, nothing is grounded to the case.? Using 50.2. So I need a MAIN circuit card.? Are card sets still available?? Does anyone have a V12 set they want to sell or an extra MAIN they want to get rid of?? Everything else works great, BPF, LPF, RF including the attenuators (which surprised me!). Thanks Mark KU3O
[email protected] All Messages By This Member #32862 Thanks Bill.? I have done this with the RF board disconnected and the audio hat off and I get the same result. I'll try reinstalling the A/D and DACs but in the mean time, can I buy a set?? Thanks for the advice. Mark
K9HZ All Messages By This Member #32863 开云体育 It’s definitely either the PCM5102 or the PCM1808, or the circuitry around those parts (I’ll bet you have a solder bridge or a bad part)… and remember that could be at those parts or at the Teensy processor (or hat)… ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? toggle quoted message Show quoted text From: [email protected] <[email protected]> On Behalf Of epif18 via groups.io Sent: Friday, February 21, 2025 2:37 PM To: [email protected] Subject: Re: [SoftwareControlledHamRadio] Excessive Noise ? Thanks Bill.? I have done this with the RF board disconnected and the audio hat off and I get the same result. I'll try reinstalling the A/D and DACs but in the mean time, can I buy a set?? Thanks for the advice. Mark
Tom - AJ8X All Messages By This Member #33019 I was dealing with the same problem. With only the Main board installed I was getting a lot of noise out of the speaker and on the spectrum display. Re-seating the PCM1808 and the PCM5102 didn't help so yesterday I changed them both ... total silence.
[email protected] All Messages By This Member #33033 Hey Tom, I've replaced the DAC and ADC and all surrounding components to no avail.? If there is a problem with the build, it's somewhere I can't get to (under a connector or something, I think unlikely).? The ADC and DACs are working, I can inject a signal into to RF IN on MAIN and I see it on the spectrum display and hear an output. ? I'm going to try to rebuild MAIN, need to find a board for sale.? I also have this pulsating noise problem on 20M that is not there when I turn the rig on (default to last freq selected) but appears when I switch bands and then come back to 20M.? The pulsating corresponds with LED 13 (SCLK to display) and with the spectrum update rate.? That SCLK also shows up on my power lines (100-200mv).? I'm running 50.2, I really believed there is a SW thing in there too but I'm just starting to look at it.? The filter adjustment stops working when I return from the menus too.? Same thing happens with 50.0.? Right in the middle of tax season! So my next step is to try the latest SW version and mess around a little with some to the constants, make sure my config is good and monitor some things to see what might be changing when I change the state of the machine.? Rebuilding MAIN is on the to do list too.? This all happens when the box is full up and when only running MAIN (no display either). I'll put out status as things develop. Good luck. Mark KU3O
K9HZ All Messages By This Member #33034 开云体育 Hey Mark… you should try the latest SW from Jack and Al. ?It all works on my 4 radios without a glitch. Also I should be back home on the 14th… so if you need any boards, i have them. ? Dr.?William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton - J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com email:??bill@... ? toggle quoted message Show quoted text On Mar 9, 2025, at 10:49?AM, epif18 via groups.io <epif18@...> wrote: ? Hey Tom, I've replaced the DAC and ADC and all surrounding components to no avail.? If there is a problem with the build, it's somewhere I can't get to (under a connector or something, I think unlikely).? The ADC and DACs are working, I can inject a signal into to RF IN on MAIN and I see it on the spectrum display and hear an output. ? I'm going to try to rebuild MAIN, need to find a board for sale.? I also have this pulsating noise problem on 20M that is not there when I turn the rig on (default to last freq selected) but appears when I switch bands and then come back to 20M.? The pulsating corresponds with LED 13 (SCLK to display) and with the spectrum update rate.? That SCLK also shows up on my power lines (100-200mv).? I'm running 50.2, I really believed there is a SW thing in there too but I'm just starting to look at it.? The filter adjustment stops working when I return from the menus too.? Same thing happens with 50.0.? Right in the middle of tax season! So my next step is to try the latest SW version and mess around a little with some to the constants, make sure my config is good and monitor some things to see what might be changing when I change the state of the machine.? Rebuilding MAIN is on the to do list too.? This all happens when the box is full up and when only running MAIN (no display either). I'll put out status as things develop. Good luck. Mark KU3O
Oliver KI3P All Messages By This Member #33035 Hi Mark, ? I thought it might be helpful to show the noise levels I get on my rig. It is a prototype rig that I use for testing software and hardware changes, so I've done nothing to try to reduce the noise. I hope it gives you a point of comparison for what "normal" is. ? If I unplug the IQ signal cable beween the RF board and the main board, this is what I get. The noisiest part of the spectrum, roughly 22 kHz from the center, is measured to be about -113 dBm. ? ? Now, plugging in the audio cable between the RF board and the main board, but leaving the antenna disconnected, I see the noise across the rest of the band rise a little: ? Finally, when I plug my 20m half-wave dipole antenna in to the radio, I see this: the 22kHz noise is still slightly above the atmospheric noise floor: ? ? Maybe some other folks with finished radios can post their results here so everyone can have points of comparison as they build? ? Cheers, Oliver KI3P ? ?
[email protected] All Messages By This Member #33036 Thanks Oliver.? This will be extremely helpful. Mark KU3O

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