Ascel AE20401 2Hz to 5.8GHz frequency counter + RF power meter kit

[TheSteve]

I haven't installed the 5.8 GHz prescaller or power meter yet, might try that tomorrow. I don't think I will be able to generate a clock high enough to really test it though, need some more test equipment for my test equipment : ).

Yes indeed, we always need more test equipment to test and verify the equipment we already have!

[bullonwheels]

I recently purchased this but getting an ~200khz on channel B if checked for frequency 2.4Ghz. Any recommendations ?

[TheBay]

Waking this thread up as there aren't any further posts on here nor other forums.

Myself and a friend ordered the AE20401 +1ppm TCXO + 5.8GHz board + 500MHz Power meter.
He initially ordered just the AE20401 + TCXO, when I ordered mine I ordered us both a 5.8GHz board and the 500MHz Power meter.

His arrived before mine so he built just the AE20401 + 1ppm TXCO kit, however using any of his references, including a 10MHz GPSD reference, a function generator and has a Gigatronics 10GHz generator the readings are all over the place, it will sometimes show the frequency but it jumps up and down by quite a few Hz so if you did not know the frequency you were inputting you would have no idea what frequency the DUT is outputting.

No issue at all with his references on a Racal Dana 1992 or other counters there.

I posted 2 videos on Youtube, is anyone else's on here behaving like this? I can only find one Youtube video with it in action reading a similar frequency and that one is all over the place.

5MHz
https://youtu.be/sCLSvnQGb5E

10MHz GPSD
https://youtu.be/VYtGDr_qtQU

[Fenstergucker]

This is a bug in the firmware. The manufacturer says it's all right, but there are some reports and measurements on the internet that prove the bug. I also have this instrument, and can confirm the error.

[TheBay]

This is a bug in the firmware. The manufacturer says it's all right, but there are some reports and measurements on the internet that prove the bug. I also have this instrument, and can confirm the error.

Yes it certainly looks like a bug in the firmware! Such a shame as it could be a really good device, I do not understand why they sell the 1ppm TCXO as it is pointless with this bug 
The reports and measurements, where on the internet is this as I'd like to read up on it.

[Fenstergucker]

I only have this link in german:
https://www.qrpforum.de/forum/index.php?thread/10258-erfahrungen-mit-ascel-ae20401/&pageNo=3

I made measurements and depending on the frequency the display always jumps around the same value. Unfortunately I don't have my notes anymore, but from 1 MHz upwards, jumps up to 40 kHz were present, always exactly the same.

I have already started to replace the microcontroller with a PIC18F with USBTMC protocol. But I haven't had time to finish everything yet.

[TheBay]

That was an interesting read!

I have been thinking about this and it has to be a firmware issue with division of binary or look up tables etc as the number is very similar every time.
Also this does not seem to happen or is as noticeable at high frequencies as the higher you go up the least significant digit changes, the 5.8GHz option is just
a prescaler, so if this was an issue with the analogue front end, calibration or source it would be even more noticeable higher up as it would be multiplied. And that's not happening.

I only have this link in german:
https://www.qrpforum.de/forum/index.php?thread/10258-erfahrungen-mit-ascel-ae20401/&pageNo=3

I made measurements and depending on the frequency the display always jumps around the same value. Unfortunately I don't have my notes anymore, but from 1 MHz upwards, jumps up to 40 kHz were present, always exactly the same.

I have already started to replace the microcontroller with a PIC18F with USBTMC protocol. But I haven't had time to finish everything yet.

[Fraser]

Maybe another email to the maker of the unit advising that the issue is now being discussed and proven on the well known and respected EEVBlog.com forum where it will be seen by many. The thought of losing sales might encourage the maker to address the issue? If not, the maker is clearly not interested in supplying a quality product and does not deserve our money. I have not used my unit enough since building it to see this problem, but I am suitably displeased to hear that the maker thought such an issue was ‘OK’.

Fraser

[TheBay]

I've sent a few e-mail back and forth with the manufacturer but they have gone quiet. They will not admit there is any issue with the Firmware  this is the last reply I had:

I've just replied to the message of your friend.
We are indeed not aware of a firmware bug causing unstable reading -
however this does occur sometimes when the input preamp adjustment is
not spot on.
One of the things we will be changing in the future is a more detailed
instruction on how to do this in the manual, and also an emphasis on how
important this is for the correct operation.
If the adjustment isn't done as it's supposed to, issues like the one
showed here may occur.

My friend had a similar reply, but was told this "It could also be a problem with the BF256 JFET, you can test this by
measuring the signal behind it - it should be as stable as the input signal.
This part is very susceptible to ESD and requires careful handling
during assembly to not damage it."

It seems they are in denial of any issues of this product and not willing to rectify it  , such a shame as it could be a great product, especially with the 5.8GHz option.
And if the source code was published then someone would have fixed this by now. I can only assume who ever wrote the original code no longer works there or something.

Maybe another email to the maker of the unit advising that the issue is now being discussed and proven on the well known and respected EEVBlog.com forum where it will be seen by many. The thought of losing sales might encourage the maker to address the issue? If not, the maker is clearly not interested in supplying a quality product and does not deserve our money. I have not used my unit enough since building it to see this problem, but I am suitably displeased to hear that the maker thought such an issue was ‘OK’.

Fraser