Working with the Version 66.9 T41 software.
This particular weirdness affects nobody but me....
I use four unused i/o bits to control my homebrew linear amplifier. They tell the amplifier what band the transceiver
is on.
These bits ( 28,29,30,31 ) were used in the V11 system to control its four-band LPF. There was an 80M pin, a 40M pin etc.
They are not used at all in the V12 system.
So I hooked them up to some transistor buffers and hence out to the linear.
V12 does have internal Yaesu codes in the LPF control card, but they are the wrong polarity. Instead of adding hardware
inverters, I just used those other four pins.
Now - with the V66.9 software, I am unable to write to those pins! The linear stays at its default - 6M. The reason
for that particular default is that it minimizes the risk of transmitting on the wrong band. If you use an LPF that is
too high, you run the risk of annoying the FCC. If OTOH you transmit through an LPF that's too low, you run the risk of
frying the expensive LDMOS final. I do have protection against that in the linear, but I am a "belt & suspenders" guy...
Back to the problem: I have verified that the code to write to those pins is being executed. ALSO, I wrote separate code at the top of loop() to write to them. No joy, no output.
BUT - I wrote a throwaway sketch - not a radio at all - to just write to those pins - actually an incrementing count. Yup, they work fine. And the linear cycles through its bands.
SO; Something in the code is preventing me from writing those pins. Gotta be one of two things: 1. Something else is writing to them. or 2) Something is pinMode-ing them to INPUTs.
Darned if I can find it though. There are some legacy places where those pins are written, but I'm pretty sure I found them all. It has worked on other versions, just not this one.
- Jerry, KF6VB
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Re: Oscillations on high bands
I ran some isolation tests today.? Below is the first page of my report (attached).
I have had an oscillation at ~35MHz in the K9HZ 20-watt
power amp in my T41 V12 (SW ver 66.4) when I press PTT in the higher
bands.? It appears to be caused by low
isolation between the PA Output, J8 and PA Input, J7, on the LPF-Control
board.? Below are several plots from my
NanoVNA showing the isolation between 21MHz and 25MHz.? On my two systems, the feedback oscillations
only occur above 22MHz.
The first plot shows the isolation with C18 removed from the
PCB.? This capacitor is the path between
the transmit and receive RF switching circuits on the LPF-Control board.? So is C7, but I didn’t bother removing that.? Isolation is better than 65dB with C18
removed.?
The next two plots show the isolation at 25MHz in the CW
mode (key down) and SSB mode (PTT) engaged.?
Isolation is in the 35dB range.?
Additionally, the poor return loss in the SSB mode indicates that the
LPF is not being connected properly.
The next plot shows isolation at 50MHz in SSB mode with PTT
engaged.? This is so bad (<25dB) that
I must have a bad RF switch.
The final two plots are done with version 50.0 at 21 and
25MHz.? Performance in CW and SSB is
identical.
?
Conclusions:
·????????
I may have a hardware problem or a test
equipment problem.? Could someone else
duplicate this test?
·????????
There is a software change in how CW and SSB are
controlled between version 50.0 and 66.4, but that bug doesn’t seem to affect
isolation.
I found that the 25 MHz and 30 MHz bands oscillate, but the lower bands don't, matching what others have found.?
?
To figure out why I measured the insertion loss from the output of the PA to the input of the PA. i.e., I connect port 0 of my NanoVNA to J8, and port 1 to J7. What this measures is the magnitude of the feedback loop.
?
?
What I found is that this is a lot higher than it should be, particularly at the higher bands.
?
| 7 MHz | 14 MHz | 21 MHz | 24 MHz | 28 MHz |
|-------|--------|--------|--------|--------|
|<-80dB | -63 dB | -53 dB | -48 dB | -47 dB |
?
I would expect roughly 40dB of insertion loss each through the T/R switch and the BPF selection switch U8. Clearly, I'm not getting that. It seems that the feedback amplitude is getting high enough at the higher bands to cause oscillations. What I would like to do next is:
?
1) Repeat this measurement for a known-good version of the code as identified by Jerry. Is this feedback path amplitude different?
2) Find the reason for the change in the feedback amplitude path by examining the LPF control signals between known-good and known-bad code.
?
Unfortunately, I am tied up for the week and won't be able to do this until next weekend.
?
?
?
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Re: boards and kits and stuff
On 2025-03-24 09:29, K9HZ wrote: Well the lesson i get from this category of devices is that mounting
the processor on the display board is preferred. But thinking about
it, all of my commercial have the processors mounted within an inch of
the processor that drives it. I guess there is some degree of
obviousness here. *** A main board bolted to the back of the display would get that cable length effectively to zero. We could use the parallel interface. Wonder if it's faster than SPI? OTOH, that would marry us to buydisplay... not sure that's where we want to go. HDMI? - Jerry, KF6VB
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Re: boards and kits and stuff
On 2025-03-24 08:39, rebruhnke via groups.io wrote: This may be sacrilegious, but I've been using the UART ports for a
long time as the comm interface between all the processors in my
radio. *** You are not alone. I recently built a little gadget for my Elecraft K2 to let it control my linear amplifier. The radio has a connector on the back for the internal "aux bus" with which all the pieces of the radio communicate. It's proprietary and undocumented. I stuck a logic analyzer on the aux bus output and discovered that it was async (aka UART ). I wrote code on a raspberry pi Pico to sniff it and figure out when the band was being changed, and to inform the linear via the 4-pin Yaesu "BCD" code. - Jerry, KF6VB
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Re: boards and kits and stuff
Well the lesson i get from this category of devices is that mounting the processor on the display board is preferred. ?But thinking about it, all of my commercial have the processors mounted within an inch of the processor that drives it. ? I guess there is some degree of obviousness here. ?
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@... ?
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On Mar 24, 2025, at 11:24?AM, Greg KF5N via groups.io <greg.electricity@...> wrote:
? It would be interesting to know what consumer devices like smartphones and tablets are using.
?
--
73 Greg KF5N
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Re: boards and kits and stuff
It would be interesting to know what consumer devices like smartphones and tablets are using.
?
--
73 Greg KF5N
|
Re: boards and kits and stuff
This may be sacrilegious, but I've been using the UART ports for a long time as the comm interface between all the processors in my radio. You even could set it up as 485 multi-drop. I mainly use command/response type of protocol; the only information that is constantly sent is the S Meter value on a timer at about 10 times a sec. Unless tuning, then the frequency information is sent for each interrupt of the tuning knob. . I've used this concept for over 30 years in my professional career as UART has been around forever. It is inherently bi-directional with the current hardware implementation and processors have a very good interrupt system for this.? Of course, this idea won't pan out if you need to stream gobs of info. The newer implementation of the UART can go to over 1Mbaud.
?
Russ
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Re: boards and kits and stuff
I need to investigate how some of the commercial radios are doing this. ?They habe experts that have spent their entire careers on just display ops so ots good to learn from 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@... ?
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On Mar 23, 2025, at 5:25?PM, ken WA2MZE <wa2mze@...> wrote:
?I guess one could use a pico (RP2040) to drive the display via the parallel interface, and talk to the Teensy via SPI.? If much of the actual graphical processing is done on the pico, then the I2C interface might be fast enough.
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Re: boards and kits and stuff
Of course there are lots of questions, and also misunderstanding of the limitations of SPI at the PJRC forums.
SPI never had a standard, but it is considered a "de facto" standard.? It was originally intended for short physical distance communication between
ICs on a PCB.? That is probably 99% of what it is being used for today.? It can be expanded with more data lines to create a serial-parallel bus.? You can
see that being used to interface to the external memory chips.
?
When you start pushing SPI off the board or increasing the clock frequency, that is where problems can begin.? For example, with the T41 pushing the SPI
through a ribbon cable and also running the clock at the maximum possible speed.? This is territory where the SPI bus shows weakness and it is up to
the designer to work around the limitations.? This is not because SPI is bad; it is because it was not designed to do this.? So if you want to make it work,
you need to be very careful with driving long cables (shunt capacitance), PCB routing, and all of the EMI implications.? This is why SPI driver chips
exist.? Same comments apply to I2C.? If you want to push the envelope with these inter-IC busses, you will need to do something extra.
?
--
73 Greg KF5N
|
Any oscillations on 10M or 6M? ? ? 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@... ? ?
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From: [email protected] <[email protected]> On Behalf Of Robert Luken W3RDL via groups.io
Sent: Sunday, March 23, 2025 10:51 PM
To: [email protected]
Subject: [SoftwareControlledHamRadio] SDTVer66.9 results? After totally scrubbing and rebuilding the IDE and libraries, I can compile and run everything again. However Ver66.4 and 66.9 only run at 600MHz if TCXO is defined. They both freeze if compiled with 528MHz. The Receive I&Q Cal worked quite well, except the button assignments don't agree with the directions. Compiled with: Faster with LTO, 600 MHz, Dual Serial SDTVer66.4
Memory Usage on Teensy 4.1:
? FLASH: code:308228, data:132408, headers:8892?? free for files:7676936
?? RAM1: variables:194528, code:284488, padding:10424?? free for local variables:34848
?? RAM2: variables:483744? free for malloc/new:40544
SDTVer66.9
Memory Usage on Teensy 4.1:
? FLASH: code:312196, data:132408, headers:9020?? free for files:7672840
?? RAM1: variables:194784, code:288584, padding:6328?? free for local variables:34592
?? RAM2: variables:483744? free for malloc/new:40544 --
73  Bob W3RDL
|
After totally scrubbing and rebuilding the IDE and libraries, I
can compile and run everything again. However Ver66.4 and 66.9
only run at 600MHz if TCXO is defined. They both freeze if
compiled with 528MHz.
The Receive I&Q Cal worked quite well, except the button
assignments don't agree with the directions.
Compiled with: Faster with LTO, 600 MHz, Dual Serial
SDTVer66.4
Memory Usage on Teensy 4.1:
? FLASH: code:308228, data:132408,
headers:8892?? free for files:7676936
?? RAM1: variables:194528, code:284488, padding:10424?? free for
local variables:34848
?? RAM2: variables:483744? free for malloc/new:40544
SDTVer66.9
Memory Usage on Teensy 4.1:
? FLASH: code:312196, data:132408,
headers:9020?? free for files:7672840
?? RAM1: variables:194784, code:288584, padding:6328?? free for
local variables:34592
?? RAM2: variables:483744? free for malloc/new:40544
--
73
Bob W3RDL
|
Re: boards and kits and stuff
Great.? You should post this on the PJRC forums then… there are hundreds of comments about the pathetic SPI hardware support in the Teensy and you can tell them differently. ? ? 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@... ? ?
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From: [email protected] <[email protected]> On Behalf Of Greg KF5N via groups.io
Sent: Sunday, March 23, 2025 8:20 PM
To: [email protected]
Subject: Re: [SoftwareControlledHamRadio] boards and kits and stuff? What I have seen from the Teensy SPI is reliable operation.? Very robust and predictable.
|
Re: boards and kits and stuff
What I have seen from the Teensy SPI is reliable operation.? Very robust and predictable.
?
--
73 Greg KF5N
|
Re: boards and kits and stuff
The problem is the Teensy SPI interface which has some defects in it...
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: www.VillaGrandPiton.com
Moderator: North American QRO Group at Groups.IO.
Moderator: Amateur Radio Builders Group at Groups.IO.
email: bill@...
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of ken WA2MZE Sent: Sunday, March 23, 2025 5:25 PM To: [email protected]Subject: Re: [SoftwareControlledHamRadio] boards and kits and stuff I guess one could use a pico (RP2040) to drive the display via the parallel interface, and talk to the Teensy via SPI. If much of the actual graphical processing is done on the pico, then the I2C interface might be fast enough.
|
Re: boards and kits and stuff
I guess one could use a pico (RP2040) to drive the display via the parallel interface, and talk to the Teensy via SPI.? If much of the actual graphical processing is done on the pico, then the I2C interface might be fast enough.
|
Re: boards and kits and stuff
Please send me your address for shipping the display driver board… ? ? 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@... ? ?
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Re: Oscillations on high bands
Good work Oliver. I’ll try to duplicate this test tomorrow? dave
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On Mar 23, 2025, at 7:36?AM, Oliver KI3P via groups.io <oliver@...> wrote:
? I found that the 25 MHz and 30 MHz bands oscillate, but the lower bands don't, matching what others have found.?
?
To figure out why I measured the insertion loss from the output of the PA to the input of the PA. i.e., I connect port 0 of my NanoVNA to J8, and port 1 to J7. What this measures is the magnitude of the feedback loop.
?
?
What I found is that this is a lot higher than it should be, particularly at the higher bands.
?
| 7 MHz | 14 MHz | 21 MHz | 24 MHz | 28 MHz |
|-------|--------|--------|--------|--------|
|<-80dB | -63 dB | -53 dB | -48 dB | -47 dB |
?
I would expect roughly 40dB of insertion loss each through the T/R switch and the BPF selection switch U8. Clearly, I'm not getting that. It seems that the feedback amplitude is getting high enough at the higher bands to cause oscillations. What I would like to do next is:
?
1) Repeat this measurement for a known-good version of the code as identified by Jerry. Is this feedback path amplitude different?
2) Find the reason for the change in the feedback amplitude path by examining the LPF control signals between known-good and known-bad code.
?
Unfortunately, I am tied up for the week and won't be able to do this until next weekend.
?
?
?
|
Re: Oscillations on high bands
I found that the 25 MHz and 30 MHz bands oscillate, but the lower bands don't, matching what others have found.?
?
To figure out why I measured the insertion loss from the output of the PA to the input of the PA. i.e., I connect port 0 of my NanoVNA to J8, and port 1 to J7. What this measures is the magnitude of the feedback loop.
?
?
What I found is that this is a lot higher than it should be, particularly at the higher bands.
?
| 7 MHz | 14 MHz | 21 MHz | 24 MHz | 28 MHz |
|-------|--------|--------|--------|--------|
|<-80dB | -63 dB | -53 dB | -48 dB | -47 dB |
?
I would expect roughly 40dB of insertion loss each through the T/R switch and the BPF selection switch U8. Clearly, I'm not getting that. It seems that the feedback amplitude is getting high enough at the higher bands to cause oscillations. What I would like to do next is:
?
1) Repeat this measurement for a known-good version of the code as identified by Jerry. Is this feedback path amplitude different?
2) Find the reason for the change in the feedback amplitude path by examining the LPF control signals between known-good and known-bad code.
?
Unfortunately, I am tied up for the week and won't be able to do this until next weekend.
?
?
?
|
Re: Oscillations on high bands
Good Morning Oliver,
Another issue that might be related is in the operation of the Audio Band Width Control.? When my radio is first turned on the bandwidth control works as it is supposed to.? Select any matrix button other than Menu and it continues to work correctly.? Select
the menu and exit the control now reverses direction and only moves the on-screen bandwidth bar a little when turning the control a lot.? Also, on the higher bands when trying to adjust PA out calibration with that control on one band it actually adjusts the
previous volume setting along with the output.? On the 10M band its effect is minimal and on the 6M band I cannot adjust the output at all as monitored on the scope on LPF output to the PA. Also, on the higher bands the scope does not show a clean sine wave
with PTT and is fuzzy. When the output is adjusted the sine wave gets fuzzy like it is being modulated by another signal unlike the lower bands which just increase and decrease in amplitude.? This started happening on the release of 063-1 Beta if I remember
correctly. I will check but believe it was ok on Ver 053.? It seemed the oscillation problem came up with the new calibration procedure and version the Al put out a few weeks ago.? All this is probably not related but will put it out there in case it turns
on a light bulb or two.
Rick, KN4AIE
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From:[email protected] on behalf of Oliver KI3P via groups.io
Sent:?Sunday, March 23, 2025 6:52 AM
To:[email protected]
Subject:?Re: [SoftwareControlledHamRadio] Oscillations on high bands
Hold the press! I was not checking the high bands. I see the oscillation on the 10m band. Back to investigating...
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Re: Oscillations on high bands
Hold the press! I was not checking the high bands. I see the oscillation on the 10m band. Back to investigating...
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K9HZ