Hi Tony! Yes, I have a couple of test programs. Email me? (good on QRZ) and I'll send them later. Working on an antenna at the moment.?
--
John P.
WA2FZW

Hello John P,
???? After all that about the attenuator I hesitate to ask; but you did also mention that you are, or were, also working on a Si4432 testing routine.
? ?? One independant of the Tiny SA could be useful.
??? Did that happen?
Thank you.
Tony jaques
(G3PTD)

Last night I finished a new signal generator S/W for an RFzero, ATSAMD21G18 that is also used in the Arduino Zero, for controlling an Si5351A. The signal generator can besides the standard carrier also generate two-tone, I/Q, H3A, spread spectrum and function as a sweep generator. It is also possible to control a LPF bank and various attenuators making the output level variable. The frequency, amplitude, output mode and more can be controlled from rotary encoders and a keypad.

See more here:

Bo
www.rudius.net/oz2m :: www.rfzero.net

Thanks for allowing me to join the group.

I have, in the past, built an early version of the PHSNA and rewritten the Arduino code to suit my purposes.? My main goal for the instrument is to test antenna capabilities.

My most often used device is a 510hz resonant speaker.? While it may seem to be a unique device, it allows me to zero beat another CW station to within 50hz or pull a weak signal out of the noise. The speaker is in line at all times when my K2 is on line.

My latest project has been a digital clock for the station.? I have an "atomic clock" hanging on the wall and quite simply, it is useless.? This project, from Jim N5IB, uses a GPS receiver to provide me with accurate second displays of my central time and Zulu time.? Jim developed the main design and I modified the Arduino code to suit my purposes.? It is now my main user device for the operating position.

I look forward to reading the mail and enjoying technical discussions.

Jay
AJ4AY
Mobile, AL

Some suggestions
Reduce the length of the wire to almost zero
Bold a heatsink to the side with the resistor
--
HBTE Files section:?/g/HBTE/files
Erik, PD0EK

That won't handle more that 50W continuous and probably has terrible
SWR above 20MHz.
Quick and dirty solution with RL > 40db up to 50Mhz good for 100W
continuos (with cooling):


On Tue, 19 May 2020 at 21:24, Dave via groups.io
<dave.kc3gpm@...> wrote:

Hello,
New to the group. Here’s a dummy load I created.
It’s a 50 ohm 250W resistor connected to a BNC bulkhead in an aluminum case (you can see the model number in the first photo).

Happy to have found the group!

73,
Dave
KC3GPM
Sent using Zoho Mail

开云体育

Thanks for accepting me to the group, Steve here in Florida, KA4NRF. Getting back into amateur radio and building projects and always loved the idea of homebrew test equipment.

Steve KA4nrf

There are many many major improvements in this version!

We did a lot of general cleanup and re-structuring of the code to make it a bit more efficient and a lot more understandable.

Moved all the definitions of things the user might want (or need) to modify into a single "My_SA.h" header file.

The software now includes a real serial command handler accessible via the USB interface. Note, it will no longer work with Erik's PC program, but the web interface effectively replaces the need fo that with much more flexibility.

Improvements to the WiFi/web interface (you'll need to reload the SPIFFS data).

Started writing a real document that explains how it works!

The code and documentation are in the Files section here.

Enjoy!
--
John P.
WA2FZW

Version 2.9 Is Available

Phil (N6WKZ) found a minor bug in the code! The time was always slightly more than a full second behind the actual time. This is fixed in Version 2.9 as well as it can be fixed.

.

The time is still a couple hundred milliseconds behind due to the delay between when the actual GPS module used on the QRP Labs GPS board sends the 1PPS pulse and when it sends the time data message.

There are no changes to the documentation, the Gerber files or the? "Where_MI" program.

Enjoy!

--
John P.
WA2FZW

Hello Erik,
??? Thank you for that, it was very helpful.
??? It never occured to me that the Banggood module, which looks like all the others,? would not be based on the 4432. I will go back and check but I'll bet that they were clever enough not to mention that detail.
?? I even traced out the circuit on the rf output side without spotting that! It is obviously very similar and the 13dBm output might even be better suited to the mixer, but I am to old to start delving into its behavour as a receiver and the software changes that would certainly be needed.
?? No I will just wait for the next two on order to come and hope that they work. One is from a supplier in England so it might even arrive today, well this week anyway.
??? By the way, I do notice that even from China the price is going up. That often indicates that availability is going down (In case potential constructors of the Tiny SA still need two).

Thank again.Tony..?

Hre you can find the data sheet of the CMT2300A



I'm not sure it is SI4432 compatible.
?
--
HBTE Files section:?/g/HBTE/files
Erik, PD0EK

Hi there,
?? I have a problem with Si4432s which someone else might have the answer to:
?? Initially I bought two green boards with the identifier HW-240 printed on them.
Only one gave an output (of -15dBm of course) when used in the local oscillator
position. So I ordered another pair, this time from from Banggood.
?? These blue boards are identified as XL2300-SMT. Neither of these produced an
output.?? So while waiting for yet another pair from yet another supplier I decided
to identify the components that would need to be removed from both boards.
Naturally neither of them had either a circuit or a layout anything like any of the
boards that have been shown in postings!
?? While doing this I noticed that the connections on the Banggood boards were
helpfully identified.? But unfortunatly they are quite different. No wonder they
didn't work!
?? The HW-240 boards do correspond to the connections given in Erik's
instructions but I give them here for comparison:

??? HW-240???? XL2300-SMT
1?? GND?????????? GND
2?? GP100??????? NC
3?? GP101??????? NC
4?? GP102??????? GP103?? Note: Connected to 6
5?? VCC??? ? ????? VDD
6?? SDO????? ? ??? NIQR
7?? SDI???????? ? ?? SCK
8?? SCLK??????? ?? SDIO
9?? nSEL???????? ? CSB
1?? nIRQ??????? ? ? FCSB
11? SDN??????????? NC
12? GND?????????? GND

?? At least GND and VCC/VDD are common so I am unlikely to have blown them up!
?? Some of the pin designations are obvious SCK and SCLK for instance, but others
are not. Can anybody translate?
??
?? I note that Eric suggests a use for GP102. Do note that this is not brought out.
I woulld guess that GP103 could not be used instead as it is tied to NIQR - whatever
that is.
?? I would suggest that potential constructors consider whether to buy the boards
from Banggood. Not just for the above reasons, but also because one of mine had
tombstoned capacitors, solder splashes on the crystal and tiny solder balls
between components.

?? I hope that this, and any answers that may be given, might help someone else
who is trying to work out why their boards from Banggood don't seem to work.

Thank you anyway.
Tony...

Marcus

You could have a look at the required drive level for you mixer.
If? it is too low harmonics will increase with higher frequencies.
--
HBTE Files section:?/g/HBTE/files
Erik, PD0EK

Hi all again,

I did another thing instead. I replaced the LO with another signal generator. One with lower harmonics, 42dBc compared to 24dBc.
The result is very similar to before, so now I've verified what Erik said. There is no need to filter the LO.

After I took the screenshots I realized that the LO power in this case was 7dBm but with the module around 4.8dBm which might explain some differences.
All in all, I've learned something today.
Cheers
Marcus

HI all,

Erik, I realize that LO harmonics is also generated in the mixer but would it not be beneficial to remove some of them beforehand? I'm aware of the fact that most mixers works better with square waves which is a fundamental frequency with an infinite number of harmonics.

Anyway I put together a LPF, it turned out to become a 400MHz one.


A quick sweep of the filter. Good performance up to 1.8GHz.

And the same spectrum picture as last time, now with the LPF on the output.

Looks much better. However when increasing frequency mixing products enters the spectrum again.

Ideally I think one would need switchable filter banks to clean this up further or just be happily aware of this simple signal generator's spurs.
I'll see if I build another LPF or a BPF for the LO just to see what happens. If I do, I'll make another post here.

Best regards
Marcus

On Wed, Apr 29, 2020 at 01:10 PM, Marcus Gustafsson wrote:

So how would one go about to reduce the mixing products in order to build a cleaner signal gen?

Hi Marcus.
Filtering the LO is not a good idea as the LO harmonics will also be generated in the mixer as it is overdriven to have good switching.
So a low pass filter at the output is the best option and yes, it will reduce the max output frequency.

?
--
HBTE Files section:?/g/HBTE/files
Erik, PD0EK

On Wed, Apr 29, 2020 at 01:10 PM, Marcus Gustafsson wrote:

So how would one go about to reduce the mixing products in order to build a cleaner signal gen?
A LPF on the LO to get rid of its first harmonic?
And a LPF on the IF output to remove the LO leakage, however this would sacrifice the max frequency or increase power rolloff unless the filter contains a trap for the LO.

Any other ideas?

I can newbie chime in on this one. I still haven't gotten past my filter designs, though did receive the 5.5x2.5mm barrel plug and opened up yesterday for the 64.5W laptop power supply to power the SH72 and see how that works interim as a most cost effective portable T12 tip soldering iron.?

A band pass filter that is tunable comes to mind.? I'm thinking that would be best.? Maybe you can gang a few ranges that can be switched.? ?

Like another way to think of is a high pass filter that is lower than the selected frequency range as well as a low pass filter that is higher than the selected frequency range.?

I'd like to read about other ideas... since I can't think of anything else off hand.? I'm guessing there might be solid state digital ASIC's now days I've not read about.?

Hi all,

I received my oscillator modules today and hooked them up:

And connected the IF output to the spectrum analyzer:

So here we can see that the generated output has harmonics around 40dBc but there are also mixing products as well and they are higher.
Peak 3 which I think is 2*LO-RF is the worst and its around 27dBc. It can be reduced by putting a suitable filter on the mixer LO input, I only had a 800MHz LPF laying around which does not suppress 2*LO (1019MHz) that much but it reduced peak 3 a bit.

So how would one go about to reduce the mixing products in order to build a cleaner signal gen?
A LPF on the LO to get rid of its first harmonic?
And a LPF on the IF output to remove the LO leakage, however this would sacrifice the max frequency or increase power rolloff unless the filter contains a trap for the LO.

Any other ideas?

Best regards
Marcus