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so how do i find where it says n7ddc etc,all i see is a load of hex code 'ff's etc,do i need special s/w,if so where do i get it from?,73+ thanks m3vuv.

i was more concerened with no hex/fw files listed,not everyone wants to trawl thry github,on here would be better more convenient.imho.

Hi all,i see some vids on yt showing the atu 100-m,it has a graphing display,is there any firmware to make the atu 100 do the same?,thanks in advance m3vuv.

Hi, Bob
No, that's too much.?

I have read that IC-705 owners use the ATU-10.? Does it tune for the 6 meter band?

73,
Bob? W7DIT

Hi David,
Excellent, the good old low level editing.
73, Dave

Hi, Dave.
There is some much easier way.?
Just open hex in Pickit3 software, find "N7DDC" sequence in the code, change it, profit.
The alphabet of hacking.?

I wanted to do the same but could see no way to do it,its pretty easy with arduino based things but pic?,seems to be a different kettle of fish!.

Ed, thanks for that info!
I had big and have now smaller issues on upper frequencies, mainly on 10m
and had shielded the cable connections with aluminium tape.
I'll give your hint with the cat6 cable a try!
--
73 de Thomas - DL7APO

Oh, and don't forget - your output harmonic filter is what it is when loaded on both sides with around 50R resistive. In all other cases it becomes an impedance transformer, which might, under certain load conditions, give you a nasty surprise. This is why I prefer using diplexer filters on the output. While they are more complex and require more parts, they actually dissipate harmonics and do not circulate them between the filter and the amp output. This allows for more "calm" output and for preventing high voltages and currents circulation within the amp boundaries.
Bill

Well, great! The display wires resonated and became antennas, common case. The world of stray currents, the destiny of the RF engineer! :)
Actually feedtrough caps should be used one side only, as not to form a PI resonant circuit, keep this in mind. In your case, entering the control system shield enclosure. 100nF is common value, but one should be prepared to change it, if any standing waves occur and mess with the signals. One always separates circuits by "fencing" signals off with series inductors, at the board/shield edge. This way one gets high impedance for RF and low for DC and LF.?
You have to play, and test, and test again, and always keep in mind, that RF amplifiers working in a dummy load are fine and dandy, but when you plug in an antenna, that presents a weird load, especially ones that "secure" high voltages on the amp output, the amps start to act crazy, stray RF gets into controls and the chase to stabilize and get all signals as expected might begin anew.
There are two highly important aspects of transistor RF amps engineering - getting all the correct shielding, filtering, etc., and protecting the RF transistors from overvoltage. Most of them can withstand high currents for short times, when presented with series resonant loads, but high voltage degrades/kills them quickly.?
Best regards!
73 de LZ1SWE
Bill

Bilyan,

Thank you for the response and suggestions.?

I was ultimately able to determine that the issues I was having were related to the display, or rather the cabling for the display. I found that unplugging it made the problem go away. I was previously using standard ribbon cable with a choke but decided to try replacing the ribbon cable with CAT6 cable (twisted pairs with unique twist ratios each) and added ferrite beads to that. That seems to have resolved the problems I was having, even on the upper frequencies.?

I was not previously aware of the existence of feed-through capacitors, so thank you for mentioning those. I'm still having an RFI problem with another component in the system (a control board for the PA) which might be helped by such a component. I just ordered some Murata feed-through caps to try out. I got a few different values from 220pf to 22000pf, the latter of which seems to be perfect for attenuating the higher frequencies I'm dealing with according to the datasheet. I'm curious, though, if you would advise putting a series inductor with the feed-through cap and, if so, what value I should use to best attenuate frequencies between 10m and 6m.?

Thanks again for your support and info!

73,
Ed

Hello Ed,
This ATU is not designed with any EMI foresight. To get it working in an RF intense environment you have to filter and shield the CPU part almost totally, especially if you have an amplifier in a close proximity. Solidly shut soldered copper box made of 0.8-1.0mm thick material, pass-trough capacitors for power and SWR signals from the bridge (which should also move around in shielded coax, not PCB tracks),?met with series inductors inside, possibly shield the SWR bridge too (keep in mind this has to be done in a proper way as not to heavily increase parasitic capacitance's). All relay control wires should pass trough flat ferrite outside the shield, pass-trough caps in the shield and series inductors inside.
How much of that you implement depends on how much EMI problems you have.
Best regards,

Hello,

I'm trying to integrate the ATU-100 into a 100W SDR-based transceiver. I'm finding that if I have the ATU too close to the amplifier (anywhere inside the same enclosure) I start to see lots of strange behaviors including but not limited to:

• Bypass going on and off?
• Power throughput not being measured
• Display glitches (pixels getting all jumbled)
• Display turning off - the ATU continues to function normally incl. button presses
• Freezing up and rebooting

These behaviors?tend?to be more pronounced on the upper bands (higher frequencies) but I've observed at least one of these behaviors on essentially every band I've tried at one point or another.?

While I didn't initially have them, I have installed the 100nF capacitors in parallel with the auto and bypass buttons but they don't seem to be helping. I've tried shielding the ATU with copper strapping and shorting the strapping to ground but that didn't seem to help either. I've also added ferrite beads around the leads for the buttons and the power input to the ATU, not to mention strewn all over the rest of the system incl. all the RF jumpers.?

I'm desperate to get this problem resolved. Any help would be greatly appreciated. Thanks in advance!

Ed

Harvey,

Where did you get the PCBs of the correct size? I'm having issues with my ATU-100 which I think may be RFI related and I'm interested in this potential fix. Do you have pictures of the finished product (outside the enclosure)?

Thanks!

Ed

Good evening,

I am working on an LDMOS amp, I would like to integrate the ATU100 into the amp for an "All in one" kind of system.?

My first step is to make sure the ATU100 can handle the power... I see there are versions rated for 1kw and 1.5kw. My amp will be maxed out at 3.8kw. But, I will only be running a max of 2.5kw.

Is there a good explanation/description of the methods used to upgrade the ATU100 to the 1 and 1.5kw?

73

John Brent

Okay. Thanks for the response.

73,

Steve
kf7o