Re: [time-nuts] Old Crystal.

Hi, in general you are right. But for a 1 MHz crystal it is fair to assume the XC0 is much higher than the crystal impedance around the series resonance. Therefore, in good approximation you can consider the crystal like a series resonance R-L-C circuit in the vicinity of series resonance. C0 c

Re: [time-nuts] Old Crystal.

@lists.febo.com Subject: Re: [time-nuts] Old Crystal. Haha - interesting pictures. It looks like they really do glow, but I doubt it's from anything the crystal element is doing - it and the mount structure may just serve as the electrodes for a gas discharge lamp. If the envelope is filled

Re: [time-nuts] Old Crystal.

> > > Thanks, > Dan > > > On 3/6/2021 12:00 PM, time-nuts-requ...@lists.febo.com wrote: > > Message: 4 > > Date: Fri, 5 Mar 2021 16:03:51 -0600 > > From: Dana Whitlow > > To: Discussion of precise time and frequency measurement > > > >

Re: [time-nuts] Old Crystal.

Haha - interesting pictures. It looks like they really do glow, but I doubt it's from anything the crystal element is doing - it and the mount structure may just serve as the electrodes for a gas discharge lamp. If the envelope is filled with some relatively "inert" gas or mixture, instead of v

Re: [time-nuts] Old Crystal.

quipment on > hand? Certainly the Q value seems unreasonably high, and Rs seems quite low. > However, these are large low frequency resonators (being 25mm in dia.). > > > Thanks, > Dan > > > On 3/6/2021 12:00 PM, time-nuts-requ...@lists.febo.com wrote: >> Mes

Re: [time-nuts] Old Crystal.

Subject: Re: [time-nuts] Old Crystal. Message-ID: Content-Type: text/plain; charset="UTF-8" Blue LEDs under Nixie tubes might have a deeper purpose than appearance- they can also help the Nixie tubes get started upon turn-on (especially if they're getting old). I

Re: [time-nuts] Old Crystal.

Blue LEDs under Nixie tubes might have a deeper purpose than appearance- they can also help the Nixie tubes get started upon turn-on (especially if they're getting old). I once stayed in a hotel room whose light switches had neon indicators to help one find them in the dark, and the one near the e

Re: [time-nuts] Old Crystal.

Ref. the original comment about a blue glow seen in a crystal, I would suggest that it was simply a blue LED used in exactly the same way that constructers of Nixie Clocks add LEDs under the Nixie tubes to make them look more dramatic. John ___ time-n

Re: [time-nuts] Old Crystal.

Hi, Sorry for the late answer. I was too busy to provide my suggestions for the measurement of those crystals. Using a network analyser, in this case you do not necessary need a PI-network with 12.5 Ohm impedance at either side of the crystal port. That PI-network was "invented" to "match" the t

Re: [time-nuts] Old Crystal.

Hi All, Many thanks to all who replied. I've beep picking my way through the suggestion, videos, and other information. The next steps will be to try to measure some of the crystal parameters with the stuff I have laying around the lab. The supplied information will keep me working on this f

Re: [time-nuts] Old Crystal.

Hi You don’t necessarily need to convert to a 12.5 ohm system. A lot depends on just what your objectives are. It a bit like needing a fancy Fluke Hart Chub thermometer if you are only after a couple of degree accuracy. The tools vary depending on the job. Bob > On Mar 1, 2021, at 3:23 PM, E

Re: [time-nuts] Old Crystal.

Using the DG8SAQ Vector Network Analyzer to identify an unknown component https://www.youtube.com/watch?v=Ao653tz1kVE actually it has a special program made for analyzing crystals Greetings and 73 KJ6UHN Alex On 3/1/2021 12:32 AM, Magnus Danielson wrote: Hi, On 2021-03-01 01:23, Attila K

Re: [time-nuts] Old Crystal.

My response got lost in the Internet, so I repeat the info. If you have access to a Network Analyzer, either Scalar or Vector,  you can measure the crystal parameters. You need a test fixture (it could be homemade) to convert the 50 Ohm analyzer impedance to 12.5 Ohm and you very slowly sweep

Re: [time-nuts] Old Crystal.

Hi Missing step from that YouTube video: Stuff a fixed resistor into the 150B and calibrate the Rm per the manual. Without that, your resistance numbers can be pretty far off. In a production setting some of the Saunders gear got “calibrated” (or at least checked) each time the frequency band

Re: [time-nuts] Old Crystal.

G3UUR and K8IQY have simple test circuits for measuring crystal motional parameters. G3UUR is great for comparing or matching a batch of similar-cut AT crystals. The K8IQY method is a bit more comprehensive for "unknown" crystals and involves very tiny step sweeping around the resonance you're in

Re: [time-nuts] Old Crystal.

This (see jpeg picture) crystal from Morion seems to have a Q of 1147576, as measured on a Saunders 150B. Youtube video of the 150B in action: Parameters from the 150B: Holder, Cs (pF), Ct (pF), Fs (MHz), Fp (MHz), Rm, C0 (pF),Cm (pF), Lm (uH), Qu Glass, 25,

Re: [time-nuts] Old Crystal.

Hi > On Mar 1, 2021, at 3:32 AM, Magnus Danielson wrote: > > Hi, > > On 2021-03-01 01:23, Attila Kinali wrote: >> On Sun, 28 Feb 2021 18:35:57 -0500 >> Dan Kemppainen wrote: >> >>> If any of you have any suggestions on where to find information on how >>> to get something like this to oscill

Re: [time-nuts] Old Crystal.

Hi > On Mar 1, 2021, at 12:52 AM, Ed Palmer wrote: > > On 2021-02-28 5:53 PM, Dan Kemppainen wrote: >> Hi All, >> >> I've picked up a couple of old crystals. Mostly because they look neat. >> They are 1Mhz, in a glass tube. The quartz is ~25mm dia, at about 1 mm >> thick. Was able to get them

Re: [time-nuts] Old Crystal.

Hi, On 2021-03-01 01:23, Attila Kinali wrote: > On Sun, 28 Feb 2021 18:35:57 -0500 > Dan Kemppainen wrote: > >> If any of you have any suggestions on where to find information on how >> to get something like this to oscillate properly, guess at correct >> parameters, or even measure any of the

Re: [time-nuts] Old crystal

They might be for an older version of the 5110A. Mine has a packaged 5 MHz TXCO like the one in the early 5061A. That 5100A/5110A combo was a real show stopper when it came out. Mine still works nicely when I switch it on but it's not really practical for most purposes. It does all the frequency sy

[time-nuts] Old Crystal.

On 2021-02-28 5:53 PM, Dan Kemppainen wrote: Hi All, I've picked up a couple of old crystals. Mostly because they look neat. They are 1Mhz, in a glass tube. The quartz is ~25mm dia, at about 1 mm thick. Was able to get them to oscillate using a Colpitts circuit. They will oscillate at 2.851Mhz (

Re: [time-nuts] Old Crystal.

I didn't realize before that there was a picture attached in the OP. That's a lot different from the HP ones. The crystal element looks more like those in regular packages, but on the large side, due to the low frequency. If it's a 1 MHz, then you should be able to find plenty of representative

Re: [time-nuts] Old Crystal.

I just took a quick look. I have four of these ovens, definitely marked for the HP5110A. One is partly disassembled so the crystal can be pulled. It looks very much like the one in the picture that Jeremy put up. There are two quite large mica caps mounted on a disc-shaped board along with the

Re: [time-nuts] Old Crystal.

Stamp on the top is 1000 kHz in Russian. David N1HAC On 2/28/21 6:35 PM, Dan Kemppainen wrote: Hi All, I've picked up a couple of old crystals. Mostly because they look neat. They are 1Mhz, in a glass tube. The quartz is ~25mm dia, at about 1 mm thick. Was able to get them to oscillate using

Re: [time-nuts] Old Crystal

> I've picked up a couple of old crystals. Mostly because they look neat. > They are 1Mhz, in a glass tube. The quartz is ~25mm dia, at about 1 mm > thick. Was able to get them to oscillate using a Colpitts circuit. They > will oscillate at 2.851Mhz (probably some strange mode) if given the > chan

Re: [time-nuts] Old Crystal.

I've got one with a similar shape crystal wafer but packaged in a glass HC6/U package. However most of the glass-packaged crystals I've seen have been in a small vacuum-tube style package with a long, narrow strip of crystal. I think 16kHz is the lowest I've seen. On Mon, Mar 1, 2021 at 12:10 AM B

Re: [time-nuts] Old Crystal.

I have some similar, that came from some old HP OCXOs. They look like they were built inside octal tube envelopes, without the pin bases. I'm pretty sure they are 1 MHz, and came from some HP51110 (I think ?) reference generators, part of one of their ancient synthesizers - it was a two-piece r

Re: [time-nuts] Old Crystal.

On Sun, 28 Feb 2021 18:35:57 -0500 Dan Kemppainen wrote: > If any of you have any suggestions on where to find information on how > to get something like this to oscillate properly, guess at correct > parameters, or even measure any of the parameters I would really > appreciate it. The best w

Re: [time-nuts] Old Crystal.

Hi Best guess is that it’s a 1 MHz fundamental. Your magic circuit is running it on the third overtone. Past that: AT cut? Probably. 32 pf load? maybe. Heated application? maybe. Russian manufacture? yup Bob > On Feb 28, 2021, at 6:35 PM, Dan Kemppainen wr

Re: [time-nuts] Old Crystal.

Hi, If you have access to a Network Analyzer, either Scalar or Vector,  you can measure the crystal parameters. You need a test fixture (homemade) to convert the impedance to 12.5 Ohm and you sweep the crystal to obtain its serial resonance and the -3dB points. From these there are formulas t

Re: [time-nuts] Old Crystal.

Is that a PR Peterson Radio logo? On Sunday, February 28, 2021, 03:53:32 PM PST, Dan Kemppainen wrote: Hi All, I've picked up a couple of old crystals. Mostly because they look neat. They are 1Mhz, in a glass tube. The quartz is ~25mm dia, at about 1 mm thick. Was able to get them to