Re: Reading OTA Transmit Frequency
Not to Hijack, but what is the module in the 8924C?? Does it power the oven only or the osc. too? Actually, I have also kept an old IFR with analog meters and TCXO calibrated at room temp after 5
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jb
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#553
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Re: VOLTMETER SELF CALIBRATION FAILED (HP 8920B)
ERROR 223 error is not caused by the power supply PSU, it should b
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Don Box
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#552
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Re: VOLTMETER SELF CALIBRATION FAILED (HP 8920B)
thanks for the info but unfortunately my power supply put on another 8920 works correctly (at least when I tested it a while ago) now I also have other problems and, perhaps because of me. I am angry
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alfonso
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#551
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Re: VOLTMETER SELF CALIBRATION FAILED (HP 8920B)
On Tue, Aug 9, 2022 at 06:00 PM, @DonBox wrote: > > On Tue, Aug 9, 2022 at 05:34 PM, zl1cvd wrote: > >> I have seen 2 causes for this type of fault. >> * Faulty power supply - check all power rails
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Don Box
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#550
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Re: VOLTMETER SELF CALIBRATION FAILED (HP 8920B)
*Thank you for your reply and suggestions.* *Power supply on the electrolytic capacitors I have replaced all, A19 on the J1 detection point +5v and -5v are normal, currently suspected of A19 data
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Don Box
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#549
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Re: VOLTMETER SELF CALIBRATION FAILED (HP 8920B)
I have seen 2 causes for this type of fault. * Faulty power supply - check all power rails are the correct voltages. These units all suffer from dry / cracked caps in power supply. The cure is to
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Chris, ZL1CVD
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#548
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Re: VOLTMETER SELF CALIBRATION FAILED (HP 8920B)
ok thank you i hope you can solve it as soon as possible i can't do anything about it now, as soon as i have the .bin file i'll upload it to the new eepromm and test it unfortunately i have to do it
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alfonso
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#547
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Re: VOLTMETER SELF CALIBRATION FAILED (HP 8920B)
This phenomenon, which I have also encountered, seems to be that certain motherboards are not plugged in properly. -- Regards, Box
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Don Box
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#546
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Re: VOLTMETER SELF CALIBRATION FAILED (HP 8920B)
-- Regards, Box
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Don Box
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#545
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Re: VOLTMETER SELF CALIBRATION FAILED (HP 8920B)
Now I can't operate anything except I can move the cursor when I turn on the computer. So after I fix ERROR 223 (A19 board), if I can operate normally, I can try to download the BIN file of A7 board
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Don Box
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#544
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Re: VOLTMETER SELF CALIBRATION FAILED (HP 8920B)
ok it doesn't matter to me, I've bought a new 28c and would like to try programming it with a definitely working .bin file to see what happens if it's not a problem for you it would be appreciated
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alfonso
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#543
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Re: VOLTMETER SELF CALIBRATION FAILED (HP 8920B)
Sorry, mine is 8920A, I don't know if the 28C of 8920A can be used on 8920B. I bought a faulty 8920A, no response to boot up, after troubleshooting, it was determined that the problem was on the A7,
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Don Box
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#542
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Re: VOLTMETER SELF CALIBRATION FAILED (HP 8920B)
excuse me, do you have a chance to make a copy of the 8920b's 28c memory in .bin format that has the calibration data in your possession for me to test? 08/08/2022 17:12, donbox@... wrote:
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alfonso
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#541
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Re: VOLTMETER SELF CALIBRATION FAILED (HP 8920B)
hello, no I have not corrected the error, but I have kept the instrument switched off for a long time and now it only does the boot. and, all the lights remain on the A7 board, you only hear the boot
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alfonso
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#540
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Re: VOLTMETER SELF CALIBRATION FAILED (HP 8920B)
hi I'm having the same problem as you and no response to any keystrokes. Did you fix this ERROR? Can you give me some advice. -- Regards, Box
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Don Box
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#539
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Re: Reading OTA Transmit Frequency
I agree about the 8920 not keeping the OCXO powered. It does come with a down side. The little switcher that does this failed in my 8924C, and I had to pretty much completely disassemble it to repair
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wspx472
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#538
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Re: Reading OTA Transmit Frequency
No modulation - It is not uncommon to walk 1 hz at a time as it warms up with averaging off, but flip back and forth then solid.? I normally enter frequency manually so it's in Freq Error mode. If
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jb
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#537
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Re: Reading OTA Transmit Frequency
The 8924C keeps the OCXO warmed up as long as it is plugged in. I ignore the last digit, maybe even the last 2. Even reading the output of a GPSDO, which is pretty stable, my 8924C jumps 1 number up
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wspx472
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#536
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Re: Reading OTA Transmit Frequency
Do the reading on an unmodulated FQ signal with no DPL.? Tone PL doesn't seem to be so bad. AVG should be at 5 to start, more than 10 and I am waiting.? You can also enable the bar graph and set the
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jb
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#535
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Re: Reading OTA Transmit Frequency
Use the Blue shift button and then the AVG botton.? Use the keypad and enter a number such as 10 or 20. The higher the number, the more delay in the updating. To clear the AVG function use the blue
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Ralph Mowery
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#534
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