@ BlacK_Chicken: Can you do a test, start with 0V input (AR will go to +12dB) and slowly turn it up. It will range down to +8dB, +4dB etc. Let me know at which point the issue appears, and between which settings it alternates.
Then again please in the 0.4V nominal setting (switch on while HOLD depressed).
It sounds to me like a relay not switching. With the test I can determine which it probably is.
Jan
Then again please in the 0.4V nominal setting (switch on while HOLD depressed).
It sounds to me like a relay not switching. With the test I can determine which it probably is.
Jan
Just made some measurements. Attached a screenshot of my scope. Blue is the AR input signal, red is the AR output. All connections unbalanced and shielded coax.
Input voltage jump from 316mV peak to 1V peak. The AR keeps on "auto-ranging" infinitively. It does not matter wheter its a up-jump to 1V or a down-jump to 1V.
Visual inspection of the PCB was OK. I checked the flat-cable connection, seems to be fine....
Input voltage jump from 316mV peak to 1V peak. The AR keeps on "auto-ranging" infinitively. It does not matter wheter its a up-jump to 1V or a down-jump to 1V.
Visual inspection of the PCB was OK. I checked the flat-cable connection, seems to be fine....
Attachments
OK, can you tell me the two settings it alternates between? Like between 0dB and -4dB, or between +4dB or 0dB?
I need to know that to be able to diagnose the problem.
Thus my request to slowly turn up the input signal from zero upwards and see what the switching does.
Does it correctly switch from +12dB (with zero input) down to +8dB, +4dB, 0dB ... when you turn up the input signal?
Jan
I need to know that to be able to diagnose the problem.
Thus my request to slowly turn up the input signal from zero upwards and see what the switching does.
Does it correctly switch from +12dB (with zero input) down to +8dB, +4dB, 0dB ... when you turn up the input signal?
Jan
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Yes, I will add it to the BOM. Right now it is mentioned in the BOM and there's a construction pic in the assembly guide, but I thought this is something most people would have lying around. It is a 0.05 inch pitch standard IDC flat cable.
A suitable one would be 3365/14-CUT-LENGTH 3M Electronic Solutions Division | Mouser Belgique from Mouser, 28awg, 7x36awg stranded at $0.42.
A suitable connector (2 needed) is Mouser 164-9007-E at $ 0.82.
Low cost unless you need to order it on itself, true. I got a length and a bag of connectors from eBay for peanuts when I started this project.
Edit: updated the Data Pack to r4 with BOM r2 including this info.
Jan
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@Black_Chicken: one more test to help me diagnose is the accuracy calibration. Switch on the AR while keeping the SE pushbutton pressed and the unit will force 0dB and wait for you to connect a signal that caused exactly 1V output (see cal procedure).
Then you press Hold and it will show the correction count for the calibration.
How much is that count?
Jan
Then you press Hold and it will show the correction count for the calibration.
How much is that count?
Jan
Will this fit for the connector (I have a open DigiKey cart).
89114-0101 3M | Connectors, Interconnects | DigiKey
89114-0101 3M | Connectors, Interconnects | DigiKey
I got my parts ordered as well. Mouser is out of stock for the reed relays, but Farnell has them in stock
Farnell order nr. 1081682
Manuf. part code: 9007-05-00 COTO TECHNOLOGY 9007-05-00 Reed Relay, SPST-NO, 5 VDC, 9007 Series, Through Hole, 500 ohm, 500 mA
For 3mm LED codes I chose were (diffuse type)
LED red LED-3MM 859-LTL-4221
LED grn LED-3MM 859-LTL-1CHG
Farnell order nr. 1081682
Manuf. part code: 9007-05-00 COTO TECHNOLOGY 9007-05-00 Reed Relay, SPST-NO, 5 VDC, 9007 Series, Through Hole, 500 ohm, 500 mA
For 3mm LED codes I chose were (diffuse type)
LED red LED-3MM 859-LTL-4221
LED grn LED-3MM 859-LTL-1CHG
Sorry for the delay, during the week Im always quite buisy with work and other things...
#1 The level was calibrated by me and the displayed levels are accurate. The display shows -4 correction counts.
#2 sweeping from 0 to 7Vrms on the SE input the AR behaves like:
* less than 0.3Vrms, +12dB
* at 0.35 Vrms, +8dB
* at 0.56 Vrms, +4dB
* at 0.85 Vrms, 0dB
* at 1.35 Vrms, -4dB
* at 2.2 Vrms, -8dB
* at 3.5 Vrms, -12dB
* at ~5.5Vrms, -16dB
downsweeping the thresholds are some millivolts lower, but essentially at the same levels.
I'll be back in the evening with more results.
#1 The level was calibrated by me and the displayed levels are accurate. The display shows -4 correction counts.
#2 sweeping from 0 to 7Vrms on the SE input the AR behaves like:
* less than 0.3Vrms, +12dB
* at 0.35 Vrms, +8dB
* at 0.56 Vrms, +4dB
* at 0.85 Vrms, 0dB
* at 1.35 Vrms, -4dB
* at 2.2 Vrms, -8dB
* at 3.5 Vrms, -12dB
* at ~5.5Vrms, -16dB
downsweeping the thresholds are some millivolts lower, but essentially at the same levels.
I'll be back in the evening with more results.
Your data shows correct operation. The -4 correction count is normal (I have seen between -9 and 0).
So it only happens when the input level changes fast? Just checked my own unit and I can bang it with whatever I want and it just settles to the correct setting. If I really try to mistreat it I see sometimes a one-step overshoot but that is all.
I need to research this. I have myself build 4 units so far and haven't seen it. Give me a day or so.
Jan
Actually, someone mentioned that there is a variant of the specified relay that has the internal snubber diode, and that IS available at Mouser. The snubber diode is not required but will work (if you mount the relays the correct way around ;-).
Jan