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| Test Equipment Anonymous (TEA) group therapy thread |
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| duckduck:
TEA in use: I bought a Kenwood UHF radio off of ebay. I programmed it to transmit on GMRS channel 01 (the Federal Communications Commission says it should be FM wide-band at 462.5625 MHz) using low power (4W). Almost all radios use 50 Ohm antennas. I tested the (low) power with a cheap SWR/power/freq meter. So, does this radio transmit on the right frequency? I plugged it into my frequency counter (through a 10W 20dB attenuator) and it looks like it is outputting on 462.56256 MHz (last digit flip/flops due to expected digital capture error). Switching the display from MHz to kHz simply "moves" the view of the captured frequency over several digits, allowing the last three digits to be read. Nothing is calibrated, so who knows what it really is, but that's certainly a good sign. Just for shiggles and gits, I plugged it into my Rigol DS1202Z-E (200 MHz, 1 GSamples/s). It actually captures a waveform of the correct frequency. Good to know. The radio should be outputting something closely resembling a sine wave (frequency modified). I assume that the displayed waveform is deformed due to the scope not grabbing enough points quickly enough. I scared myself. When I first plugged the radio into the scope, the Rigol was reading 600V p-p, or something equally crazy. Very quickly I realized that that couldn't be right because something would have blown up. Previously I had viewed mains or power tranny output using my differential probe. I dialed it back from 100x to 1x and things made more sense. This was a nice exercise for me in computing power levels through an attenuator (to keep from blowing my best TE up), and period vs frequency (to verify scope reading). I organized my RF adapters the other night. It's now a little crystal of organization in the Abyss of Messiness. EDIT: "OVER" light is lit on frequency counter when input freq is too high for selected range. This is expected when measuring 462 MHz in the kHz range. EDIT EDIT: More info about digits on the counter here (see pix of manual): --- Quote from: duckduck on July 14, 2022, 09:30:22 pm ---New acquisition: Wilson WFC-500-E frequency counter <SNIP> --- End quote --- EDIT^3: I now grok dB amplification / attenuation for voltage levels. What a wonderful system someone came up with. https://en.wikipedia.org/wiki/Decibel#History EDIT^4: Counter TCXO warmed up some more and it reads 462.56251. |
| Zoli:
--- Quote from: mnementh on July 19, 2022, 05:27:41 pm ---... Monty Python aside, I've read that a true Canadian is in fact one who knows how to make love in a canoe. One of many skills I hoped to learn up there, but alas... the dwagon family did not make it past the bureaucracy. :-DD mnem :-/O --- End quote --- I'm too old(and fat) for this kind of acrobacies, I'll leave it to the young titans; I'll stay with a (not so)short trip in a row-boat from the time when I was still full of piss and vinegar ;) ;) |
| Vince:
COMPONENT SORTING I just finished sorting that lot of 25 DIP 8 packages I had. Still a few I can't find a datasheet for... if someone has one in his computer or file cabinet... - K1150PG Well, DIP6 not DIP8, OK.... found many papers from Vishay stating it's one of their opto-couplers. So... Vishay optocoupler it is. However can't find a datasheet for it :-// - 1444A and 1444G. I found that they are ancient RTC chips made by a company that went by the name of " Eurosil ". Can't find a datasheet. All I could find is personal websites saying these chips were unreliable and that it's impossible to find a datasheet for them, ahem... Other than that, found some cool stuff : - 6N136 : super fast optocoupler, given for 1Mbps - SHARP S12ME1 , a photo... THYRISTOR (400V 200mA RMS )!!!! :wtf: Yes, apparently such things exist... maybe they make photo triacs as well... - a RS 485/422 transceiver. - DS1302 : RTC chip again. This time more recent I think, no trouble finding a datasheet for it, in PDF / modern form as well, not a crappy vintage scan. - X9313W 10K 32 step digital potentiometer |
| Neomys Sapiens:
Regarding the Tek scope setup, I aquired an additional P6245 1.5GHz active probe for 150€ with another one, whose head is held together by tape only, as a free spare. Just in time, as I can't use the probes of the company TDS7354 and someone noticed that I recently aquired a calibrated scope for myself and suggested that I could perform a urgently needed measurement at home. :palm: But don't think that I tricked myself in this matter, as the setup time for the measurement will include the performance verification etc. of the new probes and some other stuff that I can now do without undue haste while getting paid. In other news, Vince's recent post about his I-H OPAs made me notice that my last round of sample requests, which were not for direct consumption at work, lies almost a year in the past. So I started with a maxed out shopping cart at Renesas focused on fast and precision OPAs including some TO99 and Cerdip hermetics, which was duly approved. Next on the list is ADI, as they have some very interesting new HV OPAs, which I intend to be complemented with some RF parts. At TI, I think I'll focus on parts which I already have but whose stock I deem useful to bolster a bit. And hey, even longer since I called on the resources of Broadcom (formerly Avago/HP), so there we go. And I really should not let that much time pass before hitting on them again! Muahahaha! >:D |
| Neomys Sapiens:
--- Quote from: Vince on July 19, 2022, 10:14:11 pm ---COMPONENT SORTING I just finished sorting that lot of 25 DIP 8 packages I had. Still a few I can't find a datasheet for... if someone has one in his computer or file cabinet... - K1150PG Well, DIP6 not DIP8, OK.... found many papers from Vishay stating it's one of their opto-couplers. So... Vishay optocoupler it is. However can't find a datasheet for it :-// - 1444A and 1444B. I found that they are ancient RTC chips made by a company that went by the name of " Eurosil ". Can't find a datasheet. All I could find is personal websites saying these chips were unreliable and that it's impossible to find a datasheet for them, ahem... Other than that, found some cool stuff : - 6N136 : super fast optocoupler, given for 1Mbps - SHARP S12ME1 , a photo... THYRISTOR (400V 200mA RMS )!!!! :wtf: Yes, apparently such things exist... maybe they make photo triacs as well... - DS1302 : RTC chip again. This time more recent I think, no trouble finding a datasheet for it, in PDF / modern form as well, not a crappy vintage scan. - a RS 485/422 transceiver. --- End quote --- I'm not sure where Vishay aquired their optoelectronic line, but the only OC with a leading K which I have (K8031P) is an old TFK part, so maybe your K1150PG could be one too? |
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