Reply by Cursitor Doom October 17, 20192019-10-17
On Thu, 17 Oct 2019 09:24:41 +0000, Jan Panteltje wrote:

> So, now I am curious, where are you located then?
Elsewhere in Yurp. It'll take me 48hrs to get to that hamfest so there's no excuse for you not to make the effort from your position "just up the road." :-)
> or is that only known to Russian agents ;-)?
Believe me, it's not the Russians you need to worry about.
> I am all the way in the north of the Netherlands, 'Friesland'.
Ah yes, I know it well (the location anyway). So that's a date then! Next March at the hamfest. I'll be wearing a red carnation, bright orange flared trousers and a tinfoil hat. See you there! :) -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition.
Reply by Jan Panteltje October 17, 20192019-10-17
On a sunny day (Thu, 17 Oct 2019 08:13:45 -0000 (UTC)) it happened Cursitor
Doom <curd@notformail.com> wrote in <qo97rp$2hf$3@dont-email.me>:

>On Thu, 17 Oct 2019 07:31:23 +0000, Jan Panteltje wrote: > >> Again, do you have a cellphone? > >Yes, of course. HATE the damn thing, but there's no avoiding them. What >are you driving at, dear boy?
In that cellphone there is a lot of precision RF stuff, filtering etc, mostly integrated in one chip that is smaller than even one of your mica caps... If you like 'precision' filtering, then I have a super-conducting filter from a cell[phone tower here.... At 70 degrees Kelvin the R of the inductors is zero, so the Q is enormous, that filter is attenuating any out of band signals in the cellphone band (in the tower). http://panteltje.com/pub/super_filter/super_filter_dewar_img_2557.jpg also a bit of a boat-anchor :-) http://panteltje.com/pub/super_filter/super_filter_front_plate_img_2576.jpg
Reply by Jan Panteltje October 17, 20192019-10-17
On a sunny day (Thu, 17 Oct 2019 08:00:46 -0000 (UTC)) it happened Cursitor
Doom <curd@notformail.com> wrote in <qo973e$2hf$2@dont-email.me>:

>On Thu, 17 Oct 2019 06:46:42 +0000, Jan Panteltje wrote: > >> No, I think you mean 'Rosmalen', that was in March this year. >> Did not go there, is a ham radio market, I do have a callsign though. >> https://amateurzender.nl/events/radiomarkt-rosmalen/ >> >> Already have enough stuff :-) > >Same here! Far too much stuff in fact. Well, if you're not too far away >why not pop over and meet up at the next one? And don't worry - I'm not >gay! >:-D
So, now I am curious, where are you located then? or is that only known to Russian agents ;-)? I am all the way in the north of the Netherlands, 'Friesland'. Well now anyways, lived all over the place.
Reply by October 17, 20192019-10-17
On Wednesday, 16 October 2019 17:37:41 UTC+1, jrwal...@gmail.com  wrote:
> On Wednesday, 16 October 2019 16:24:34 UTC+1, Winfield Hill wrote: > > Jan Panteltje wrote... > > > > > > I bought a 2400 W water boiler, for coffee that is. > > > Plugging it in did indeed boil 1.5 liter water in > > > about 3 minutes, but it also caused a dip ... > > > > 2400 watts, that's ridiculous. The most they sell > > here is 1500 watts, that's more than fast enough. > > Trade it in for a smaller one. > > Not at all. I just checked the rating label on my "electric kettle". > (Almost every household in the UK has one of these.) > Mine is rated at 220 - 240V, 2500 - 3000W. > > Most UK household mains supplies are about 240V single phase and > have a main fuse rated at 80 or 100A. Larger houses often have > 3-phase 240V (phase to neutral) at 100A per phase. > > (The "official" voltage is 230V but this is just for harmonisation > purposes with the rest of the EU. The specified tolerances allow > the real voltage to be around 240V for most areas.) > > John
Domestic supplies are variously rated at 40A, 60A, 80A and 100A. 40 is common in 1&2 bed flats. There are also pre-war 30A supplies still in use, even in houses where one would expect much better. In my limited experience of the latter they coped with way above 30A well enough. 230v is the nominal voltage only - the target voltage is still 240v. NT
Reply by Cursitor Doom October 17, 20192019-10-17
On Thu, 17 Oct 2019 07:31:23 +0000, Jan Panteltje wrote:

> Again, do you have a cellphone?
Yes, of course. HATE the damn thing, but there's no avoiding them. What are you driving at, dear boy? -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition.
Reply by Cursitor Doom October 17, 20192019-10-17
On Thu, 17 Oct 2019 06:46:42 +0000, Jan Panteltje wrote:

> No, I think you mean 'Rosmalen', that was in March this year. > Did not go there, is a ham radio market, I do have a callsign though. > https://amateurzender.nl/events/radiomarkt-rosmalen/ > > Already have enough stuff :-)
Same here! Far too much stuff in fact. Well, if you're not too far away why not pop over and meet up at the next one? And don't worry - I'm not gay! :-D -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition.
Reply by Cursitor Doom October 17, 20192019-10-17
On Wed, 16 Oct 2019 17:38:14 -0700, Winfield Hill wrote:

> Cursitor Doom wrote... >> >> On 16 Oct 2019, Cursitor Doom wrote: >> >>> Well I'm mightily relieved you said that, Win, because I do happen to >>> have a very large amount of both polarities in stock. THANKS!!! :) >> >> Just wondering if I should try to match pairs by Beta as closely as >> possible. I have a nagging suspicion I really should make that extra >> little bit of effort. > > Although this is an old design, it adheres well to the BJT design > philopsohy I learned in the late 60s. Which is to rely on accurate > Ebers-Moll transconductance characteristics, and stay away from the > uncertain beta, and similar aspects of a transistor, in the circuit > design. So you don't need to match beta, Vbe, or other perameters.
Thanks, Win, that's a real plus, believe me. I'm carrying out some other tests in the odd minutes I get between the phone ringing and various people calling and have ascertained the *actual* fault appears to be in one of the preceding stages. So at the moment, it looks like there's nothing wrong with that "partially C-E shorted bjt" - it's simply being driven into saturation by a chain of cause and effect from an earlier stage where the true fault *does* lie. I'm guessing this is not unusual when you have directly-coupled stages like these, which I'm not so much accustomed to dealing with. I'll be investigating further over the next 8 hours as and when time and interruptions permit and will report back in due course.... Thanks again for your invaluable assistance! -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition.
Reply by Jan Panteltje October 17, 20192019-10-17
On a sunny day (Thu, 17 Oct 2019 04:38:03 -0000 (UTC)) it happened Jasen Betts
<jasen@xnet.co.nz> wrote in <qo8r7b$m2a$1@gonzo.revmaps.no-ip.org>:

>On 2019-10-16, upsidedown@downunder.com <upsidedown@downunder.com> wrote: >> On Wed, 16 Oct 2019 07:31:21 GMT, Jan Panteltje >><pNaOnStPeAlMtje@yahoo.com> wrote: >> >>>LOL >>>not everybody is the same, I am fighting with software. >>>Real fun, my systems got attacked by one of the most evil ones, the well known Jan Panteltje. >>>I bought a 2400 W water boiler, for coffee that is. >>>Plugging it in did indeed boil 1.5 liter water in about 3 minutes, but it also caused a dip in the mains >>>that in turn caused my main PC reiserfs to see bad sectors, >>>Rescue failed. >> >> 2400 W is only 10 A steady state i.e. 24 ohm resistance. >> >> Unfortunately the cold resistance is quite low, until the resistor >> reaches nominal operating temperature, so the cold start current can >> be much larger than 10 A. > >It could be as low as 22 ohms when cold. but I can't see an xtra half-amp >making a big difference.
Indeed, I measred the change for an electric heater spiral, not really much betwen cold and glowing red. It is different for filament (Edison type) bulbs, that maybe be a factor 10.
Reply by Jan Panteltje October 17, 20192019-10-17
On a sunny day (Wed, 16 Oct 2019 23:39:41 -0000 (UTC)) it happened Cursitor
Doom <curd@notformail.com> wrote in <qo89nt$4lg$6@dont-email.me>:

>On Thu, 17 Oct 2019 09:38:31 +1100, Clifford Heath wrote: > >> The RTL-SDR (listening) community seems to think that this genuine >> "RTL-SDR v3 Blog" version is very much better than the cheap generic TV >> dongles that have the same chipset. Ok, I grant that it has a TCXO and >> the "Q-branch" mod for HF listening, but... >> >> What else is it about this specific dongle that makes it better? If you >> know and have time to answer, of course... > >SDR is pretty amazing for its size and cost, but in terms of sensitivity >and selectivity you really cannot beat good old fashioned physical >components built specifically for the purpose: rock solid silver mica >capacitors and carefully cut and trimmed, temp-stabilised quartz crystals >for frequency control; large, open wound, well-spaced gold plated >inductors for high Q tuned circuits. You'll never successfully emulate >qualities like those in software. NEVER!!
No T-Ford either! Again, do you have a cellphone?
Reply by Jan Panteltje October 17, 20192019-10-17
On a sunny day (Thu, 17 Oct 2019 09:38:31 +1100) it happened Clifford Heath
<no.spam@please.net> wrote in <HZMpF.21095$5X.7513@fx15.iad>:

>On 15/10/19 7:20 pm, Jan Panteltje wrote: >> I was referring to mixing down 2.4 GHz to 1.5 GHz or so for use with an RTL_SDR USB stick as spectrum analyzer, >> that I did. >... >> So, as to GHz: >> https://www.ebay.com/itm/272411458376 >> much more fun to play with than old boat_anchors. >> that is what my xpsa spectrum analyzer software runs on. > >The RTL-SDR (listening) community seems to think that this genuine >"RTL-SDR v3 Blog" version is very much better than the cheap generic TV >dongles that have the same chipset. Ok, I grant that it has a TCXO and >the "Q-branch" mod for HF listening, but... > >What else is it about this specific dongle that makes it better? If you >know and have time to answer, of course... > >Clifford Heath
Well I have the time, nyways what is time .. relativity.. OK As with everything (like cars) people have preferences. Indeed the TCXO is great, But .. you can specify angt frequency error in rtl_sdr with the -p flag to compensate. When you have the thing warm up for some time even without TCXO the drift is maybe 2 ppm (for my old ones that is). For most purposes that is fine. I have a rubidium reference (ebay) and cheched the ebay TXCO sticks against it, and for one I added a 1 ppm correction (assuming the rubidium is exact). Good enough for me. As to sensitivity I am not sure, seems much the same to me. I did GPS with the E4000. I have 2 of the ebay TCXO ones, rtl_test shows this on the laptop: ~# rtl_test Found 1 device(s): 0: ezcap USB 2.0 DVB-T/DAB/FM dongle Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle Found Rafael Micro R820T tuner Supported gain values (29): 0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6 Then I have a very old no TCXO one that one runs on a Raspberry Pi receiving AIS (ship data): root@raspberrypi:~# rtl_test Found 1 device(s): 0: ezcap USB 2.0 DVB-T/DAB/FM dongle Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle Found Rafael Micro R820T tuner Supported gain values (29): 0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6 So that one looks a lot like the same chip, but no TCXO, corection needed +46 ppm Rx AIS with the one: rtl_fm -f 161975000 -p 46 -s 48k -r 48k | aisdecoder -d -h 127.0.0.1 -p 10123 -a file -c mono -f /dev/stdin And then I have an old nice E4000 with a wider frequency range: ~ # rtl_test Found 1 device(s): 0: Generic RTL2832U (e.g. hama nano) Using device 0: Generic RTL2832U (e.g. hama nano) Found Elonics E4000 tuner Supported gain values (14): -1.0 1.5 4.0 6.5 9.0 11.5 14.0 16.5 19.0 21.5 24.0 29.0 34.0 42.0 That one has a few ppm error too, but the larger frequency range is great, I rebuild it mounting the PCB in a dycast box. E4000 tuner is maybe harder to find these days, no TCXO. So it depends. For testing I just always use a TCXO one. Very nice things to have, one in use to receive data from a cheap 433 MHz wireless weather sensor mounted outside under the garden table uses 'rtl_433' software. Planes with 'dump1090'. http://panteltje.com/panteltje/xpsa/index.html Note the harmonic factor button, say you have 144 MHz, just press it to 2 and you see 288, 432, etc etc tells you a lot about your filtering :-) In the olden days in broadcasting we used to test the eurovision audio lines with 1000 Hz, and then measure the amplitude of 2000, 3000, 4000, etc .. do the math and get distortion. No scope in the world ... ! That also works for MHz.. Just scan the spectrum, last week I was searching for some interference, came from a HDMI cable...