Not Displaying the Frequency....
...When tuning.
The tuning of the T41 ( V12, I2C front panel, I2C encoders ) is unpleasant. As you tune around, you get tiny
blips of sound, interspersed with long display updates. You basically cannot hear what you're tuning past.
I just tried commenting out the bit of code that displays the frequency as you tune. Tuning is much better.
There is still a burst of nasty noise with each encoder *tick*, but it's short, and you can easily hear what you're
tuning past.
Naturally, that's not a real fix. The instant you start tuning, the frequency display is wrong...and that's just wrong!
What would be a fix? A few things: First of all, we *could* do a timer thing where we don't bother to display
the frequency until we stop tuning. There was tuning, and now there isn't? Ok, display where we got to. Still not optimal.
I note that it always updates ALL the digits of the frequency, even those that haven't changed. It even
redisplays the VFO B frequency. Surely it doesn't need to update all that.
Also - I wonder why on earth the audio pauses or stops or gets discarded while it writes the display? Surely
audio interrupts can continue during this time....?
- Jerry, KF6VB
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Re: T41 receive attenuator working?
The latest RF boards have holes in the back, behind the PE4302 chips for easier soldering the back pad. ?That said, ill look into having RF boards made with the PE4302¡¯s and the si5351 pre placed. ?I don't think that would cost much. ?
Dr.?William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton - J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com
email:??bill@... ?
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On Feb 1, 2025, at 9:35?AM, jerry-KF6VB <jerry@...> wrote:
? On 2025-02-01 06:53, D Solt via groups.io wrote:Thanks Jerry. ?I now have 3 boards built with the attenuator and the
spectrum doesn't move up and down on any of them. ?I'll try monitoring
right at the attenuator with a sig gen input. ?It is a difficult chip
to install and I'm guessing I don't have it soldered on all pins.
*** Yeah, I think I had to install two or three before it finally worked.Those chips - and the si5351a - really beg for pick-n-place.I think it worked after... ?...I got some low temperature solder paste and diluted it with liquid flux.Put a tiny drop on each land under a microscope with a brand new Xacto knife tip.Soldered it on a little computerized hot plate. ???????????????????- Jerry, KF6VB
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Re: T41-EP V11 PA Board JP1 Reference
Thanks Greg. I will do the bias adjustment and then remove the
resistor.
?
73 Rocco
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From: Greg KF5N via groups.io
Sent: Saturday, February 1, 2025 3:46 AM
Subject: Re: [SoftwareControlledHamRadio] T41-EP V11 PA Board JP1
Reference
?
Hi Rocco, the jumper is used only for setting the bias of the IRF510
transistors.
It forces the bias voltage generator circuitry to ON.? So it is only
used temporarily, in the preliminary tune-up of the amplifier.
?
--
73 Greg KF5N
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Re: More on the display driver
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Re: T41 receive attenuator working?
On 2025-02-01 06:53, D Solt via groups.io wrote: Thanks Jerry. I now have 3 boards built with the attenuator and the
spectrum doesn't move up and down on any of them. I'll try monitoring
right at the attenuator with a sig gen input. It is a difficult chip
to install and I'm guessing I don't have it soldered on all pins. *** Yeah, I think I had to install two or three before it finally worked. Those chips - and the si5351a - really beg for pick-n-place. I think it worked after... ...I got some low temperature solder paste and diluted it with liquid flux. Put a tiny drop on each land under a microscope with a brand new Xacto knife tip. Soldered it on a little computerized hot plate. - Jerry, KF6VB
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Re: T41 receive attenuator working?
Thanks Jerry.? I now have 3 boards built with the attenuator and the spectrum doesn't move up and down on any of them.? I'll try monitoring right at the attenuator with a sig gen input.? It is a difficult chip to install and I'm guessing I don't have it soldered on all pins.
dave, n3ds
When I change the attenuator, I can see it clearly across the entire
spectrum display.? Everything just moves down.
? ? ? ? ? ? ?- Jerry, KF6VB
On 2025-01-31 17:15, D Solt via wrote:
> Thanks Oliver. I¡¯ll try this
> dave
>
>> On Jan 31, 2025, at 6:14?PM, Oliver KI3P via
>> <oliver=[email protected]> wrote:
>
>> ?
>>
>> Here's one way to test it.
>>
>> Load the latest code onto the Teensy. It has an option under the RF
>> set menu to change the input attenuation.
>>
>> Then, put a 10 MHz (or whatever) signal into the RF_in SMA connector
>> and hook an oscilloscope or spectrum analyzer to the output side of
>> the attenuator bypass jumper.
>>
>> You should see the signal amplitude change when you adjust the RF
>> input attention setting in the RF menu.
>>
>> -------- Original Message --------
>> On 1/31/25 9:46 AM, D Solt via wrote:
>>
>>> How do I tell if the receive PE4302 attenuator is working.? I
>>> can't tell any difference in received signals at whatever settings
>>> or when I jumper it out.? I have two RF boards built up and they
>>> behave the same.? Before I swap the chips out, I wanted to get
>>> some inputs. I haven't gotten to testing the transmitter circuits
>>> yet.
>>> dave, n3ds
>
>
>
> Links:
> ------
> [1] /g/SoftwareControlledHamRadio/message/32529
> [2] /mt/110916510/243852
> [3] /g/SoftwareControlledHamRadio/post
> [4] /g/SoftwareControlledHamRadio/editsub/243852
> [5]
> /g/SoftwareControlledHamRadio/leave/10484476/243852/1943518115/xyzzy
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Re: More on the display driver
Wont matter what side of the board you solder it/ plug it into¡ just put the connectors on the opposite side of the board and keep the board faced the same way¡ meaning the chip faces the BACK SIDE of the board. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C 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 Tim via groups.io
Sent: Saturday, February 1, 2025 7:22 AM
To: [email protected]
Subject: Re: [SoftwareControlledHamRadio] More on the display driver? For those who have not populated board yet could there be an additional version that soldered to back side of board? Would make sense for 7" display
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Re: More on the display driver
For those who have not populated board yet could there be an additional version that soldered to back side of board?
Would make sense for 7" display
Tim
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Re: T41-EP V11 PA Board JP1 Reference
Hi Rocco, the jumper is used only for setting the bias of the IRF510 transistors.
It forces the bias voltage generator circuitry to ON.? So it is only used temporarily, in the preliminary tune-up of the amplifier.
?
--
73 Greg KF5N
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More on the display driver
I put together a mock-up of the display driver.? The board will look like this (that is the real ISO 7241M on the board¡the board is from a previous attempt): ? 
? I envision it plugging into the display port and will extend OVER the interior of the MAIN board like you see in this picture: ?  ?
? Or ? 
? That way it does not extend outside of the MAIN board perimeter¡ so will not interfere with your current T41 V12 layout in your radio chassis.? You can see hot the display cable will plug into the board.? ?It won¡¯t take long to generate gerbers and get boards¡the schematic is simple.?? ?I¡¯ll get with Oliver tomorrow to see if he can knock out the PCB and I¡¯ll get a bunch made. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C 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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Many thanks for the comments , here and separately.? That is most helpful for me.
?
Additional note:? I have posted stuff about the RF design, including the three plug-in networks.? It is about half-way down in
under "Tuned Circuits."? This includes schematics and layouts for the three plug-in networks.?
?
More testing is going on and I will get that up as I can.
?
73, Bob? W7PUA
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Re: T41 receive attenuator working?
When I change the attenuator, I can see it clearly across the entire
spectrum display. Everything just moves down.
- Jerry, KF6VB
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On 2025-01-31 17:15, D Solt via groups.io wrote: Thanks Oliver. I¡¯ll try this
dave
On Jan 31, 2025, at 6:14?PM, Oliver KI3P via groups.io
<oliver@...> wrote: ?
Here's one way to test it.
Load the latest code onto the Teensy. It has an option under the RF
set menu to change the input attenuation.
Then, put a 10 MHz (or whatever) signal into the RF_in SMA connector
and hook an oscilloscope or spectrum analyzer to the output side of
the attenuator bypass jumper.
You should see the signal amplitude change when you adjust the RF
input attention setting in the RF menu.
-------- Original Message --------
On 1/31/25 9:46 AM, D Solt via groups.io wrote:
How do I tell if the receive PE4302 attenuator is working. I
can't tell any difference in received signals at whatever settings
or when I jumper it out. I have two RF boards built up and they
behave the same. Before I swap the chips out, I wanted to get
some inputs. I haven't gotten to testing the transmitter circuits
yet.
dave, n3ds Links:
------
[1] /g/SoftwareControlledHamRadio/message/32529
[2] /mt/110916510/243852
[3] /g/SoftwareControlledHamRadio/post
[4] /g/SoftwareControlledHamRadio/editsub/243852
[5]
/g/SoftwareControlledHamRadio/leave/10484476/243852/1943518115/xyzzy
|
Re: T41 receive attenuator working?
Thanks Oliver. I¡¯ll try this dave
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Show quoted text
On Jan 31, 2025, at 6:14?PM, Oliver KI3P via groups.io <oliver@...> wrote:
? Here's one way to test it.
Load the latest code onto the Teensy. It has an option under the RF set menu to change the input attenuation.
Then, put a 10 MHz (or whatever) signal into the RF_in SMA connector and hook an oscilloscope or spectrum analyzer to the output side of the attenuator bypass jumper.
You should see the signal amplitude change when you adjust the RF input attention setting in the RF menu.
-------- Original Message -------- On 1/31/25 9:46 AM, D Solt via groups.io wrote: How do I tell if the receive PE4302 attenuator is working.? I can't tell any difference in received signals at whatever settings or when I jumper it out.? I have two RF boards built up and they behave the same.? Before I swap the chips out, I wanted to get some inputs. I haven't gotten to testing the transmitter circuits yet.
dave, n3ds
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Re: T41-EP V11 PA Board JP1 Reference
Hi Greg,
?
I have a question regarding the JP1 pads between U2 and C24 on the V11 PA
board. I have a zero ohm resister there now but not sure why.
According to the schematic it looks like it should be a two pin jumper not
a resistor pad. I built the board quit awhile back and I can¡¯t
find anywhere in my notes about it. I searched the site and couldn't find
anything there either. How did you deal with it? I¡¯m just trying to
complete the project so I can move on.
?
73 Rocco WJ6U?
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Re: T41 receive attenuator working?
Here's one way to test it.
Load the latest code onto the Teensy. It has an option under the RF set menu to change the input attenuation.
Then, put a 10 MHz (or whatever) signal into the RF_in SMA connector and hook an oscilloscope or spectrum analyzer to the output side of the attenuator bypass jumper.
You should see the signal amplitude change when you adjust the RF input attention setting in the RF menu.
-------- Original Message -------- On 1/31/25 9:46 AM, D Solt via groups.io wrote: How do I tell if the receive PE4302 attenuator is working.? I can't tell any difference in received signals at whatever settings or when I jumper it out.? I have two RF boards built up and they behave the same.? Before I swap the chips out, I wanted to get some inputs. I haven't gotten to testing the transmitter circuits yet.
dave, n3ds
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Re: MKV VIDOR 4000 shows up
"
not much support from the Arduino crowd."
I'm sorry to hear that, but not surprised. I looked at it two or three years?ago when I wanted eight fairly high speed counters connected to?a microcontroller. It seemed like quadrature counter IP could do it but no one on the official Arduino forum could tell me if it would work or how to do it.
The other two or three boards mentioned here look more interesting, and with this news, they don't have the stigma of maybe not being around as long as some other options.
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Re: [AmateurRadioBuilders] New Display Driver
You could use pointers because the indices are no different that an index except increment by one moves the byte pointer by sizeof(measure) bytes. Indeed the expression:
??????? int measure[100]; ??????? int x;
??????? x = measure[10];
is no different than:
??????? x = *(&measure + (sizeof(int) * 10));
They are syntactically the same.
Jack, W8TEE
On Friday, January 31, 2025 at 02:36:21 PM EST, jerry-KF6VB <jerry@...> wrote:
On 2025-01-31 10:36, jjpurdum via groups.io wrote:
> I can't remember for certain, but I think I did try using a ring
> buffer when we first started the project, but I couldn't get it to
> work correctly. Perhaps I don't understand how we get the rollover for
> free? A program pointer is only 32 bits, so the ring buffer could hold
> 8 program pointers before it rolls over. The fact that you're
> incrementing the index suggests that's the case. Once it rolls over,
> we're back to the head of the buffer which is non-zero from the 8
> prior calls. At some point, the old address needs to disappear using
> that algorithm. You could accomplish the same thing without a ring
> buffer by just saving the return address and using it once the ISR
> finishes. I also tried that early on, but I never got it to work
> reliably. Since it must be easier than I understand it, perhaps you
> could give me the code and I'll test it.
Here's a test program I adapted for the power/SWR sensor in the K9HZ LPF
control
board.? It uses a timer interrupt to poll the device.? There is a
256-entry
circular buffer addressed by a pair of byte indices.? Note that these
are
INDICES, not pointers.? The concept won't work with pointers.? Note also
that
the struct containing the measurements is volatile.
I once wrote a program that converted a fast 286 PC ( this was in the
80's ) into
a recording oscilloscope.? The CPU had a system of registers and
"segment registers".? Each
ordinary register was 16-bit and addressed therefore 64K.? I used a 64K
circular buffer,
and got the rollovers for free because with 16 bits 0xffff + 1 = 0.
? ? ? ? ? ? ? ? ? ? ? ? ? - Jerry, KF6VB
-- Jack, W8TEE
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Re: MKV VIDOR 4000 shows up
Interesting project.? I have a different FPGA board waiting for my attention.
?
I recently spent about a month working with an (dual core Arm Cortex M7/M4).  There is a bit of a learning curve for the dual core chip even if you're familiar with the STM tool chain.? The learning curve is huge if you're not.? It took me about two days to get a blink program running on each core (the board has 4 LEDs for user use). ?I quickly came to realize how much we benefit from the work PJRC put into the T4.1. ?
?
During my time with the board, I was able to get the two cores talking together with some of my DSP routines running on the M7 core and some graphing routines running on the M4 core, which controlled the display.? However, my plan was to have a complete mockup of the T41 on the board in a quarter of that time.? In the end I put the project on hold because the display controller on the development board would require a sizable rewrite of the T41 display code.? I wasn't willing to do that for a mockup of the T41.? I have other projects that I'd rather spend time on.
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Re: MKV VIDOR 4000 shows up
On 2025-01-31 11:56, K9HZ wrote: This board has 1) an arduino processor and 2) a Cyclone 10 FPGA on the
same board. It supports a variety of I/o and HDMI display interface. *** HDMI? Now that *is* interesting. Is it connected to the FPGA? Is there IP available to drive it? - Jerry, KF6VB
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Re: MKV VIDOR 4000 shows up
This board has 1) an arduino processor and 2) a Cyclone 10 FPGA on the same board.? It supports a variety of I/o and HDMI display interface.? It sounds like a lot of cool stuff.? Now, I would never use this board in a radio project... but I might use the ships on MY MAIN board... ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C 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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K9HZ
jjpurdum