Re: [time-nuts] ``direct'' RS-232 vs. RS-232 via USB vs. PPS decoding cards

On 14/02/2017 12:24 AM, Chris Albertson wrote: Pretty dramatic difference between a "real" serial port and USB. Like two orders of magnitude or more. If you computer lacks a serial port, just buy a new computer. The Raspberry Pi or the like costs about $40 the serial port has a pin that

Re: [time-nuts] ``direct'' RS-232 vs. RS-232 via USB vs. PPS decoding cards

Pretty dramatic difference between a "real" serial port and USB. Like two orders of magnitude or more. If you computer lacks a serial port, just buy a new computer. The Raspberry Pi or the like costs about $40. But the money you save on electric power will pay off that $40 in less than a

Re: [time-nuts] Vintage Frequency Measurement

just be careful, because if you under-heat the cathode you could kill it 73 Alex On 2/13/2017 7:11 PM, Bob Camp wrote: Hi On Feb 13, 2017, at 8:15 PM, Scott Stobbe wrote: On Mon, Feb 13, 2017 at 6:41 PM, Bob Camp wrote: I think what you would

Re: [time-nuts] Vintage Frequency Measurement

Hi > On Feb 13, 2017, at 8:15 PM, Scott Stobbe wrote: > > On Mon, Feb 13, 2017 at 6:41 PM, Bob Camp wrote: > >> >> >> I think what you would find is that it *is* a fairly normal AT cut and the >> data book >> that came with the instrument plotted

Re: [time-nuts] Vintage Frequency Measurement

On Mon, Feb 13, 2017 at 6:41 PM, Bob Camp wrote: > > > I think what you would find is that it *is* a fairly normal AT cut and the > data book > that came with the instrument plotted out the data for the specific > crystal in > the device. The usable temperature range was fairly

Re: [time-nuts] Vintage Frequency Measurement

Agreed, it's probably reasonable to say that a real absorption wavemeter would (a) have to have a meter or some other visual indicator; and (b) likely be powered exclusively by the energy its tank circuit "absorbs." The BC221/LM boxes fall a little short of both requirements. -- john,

Re: [time-nuts] Vintage Frequency Measurement

Hi > On Feb 13, 2017, at 10:35 AM, Scott Stobbe wrote: > > Hi Mike, > > First of all, Wow what an interesting read, thanks for sharing some of the > history and your experiences with the 105. A second thanks for uploading > the manual, which I found to be a great

Re: [time-nuts] Vintage Frequency Measurement

Hi With a VFO running, you have a heterodyne frequency meter. That is (at least to me) a very different device than an absorption wave meter. I know way to put power into a BC-221 and use it as an absorption device. I’m not in any way saying that the LM or the 221 are less useful. They are

[time-nuts] TICC shipments

Hi All -- The production batch of TICCs has arrived at TAPR and the first shipments to customers are going out today. It will probably take another few days to get them all sent -- there are nearly 100 units going out the door! As previously mentioned, the TICCs have been loaded with

Re: [time-nuts] Vintage Frequency Measurement

You could use it as an absorption wavemeter, in its broadest sense of a passive tuned circuit with an indicating load. The headphone jack was normally used to calibrate the VFO against a harmonic of the internal crystal oscillator, but it could zero beat an external source as well. It

Re: [time-nuts] Vintage Frequency Measurement

On 2/13/2017 12:56 PM, Brooke Clarke wrote: Wes: Is this the patent for the IMPATT diode power amplifier? https://patents.google.com/patent/US3931587 No. As I recall the designer (or at least a prime mover) was a guy named Eisenhart. The Hughes organization at the time had engineering done

Re: [time-nuts] Vintage Frequency Measurement

On 02/13/2017 10:35 AM, Scott Stobbe wrote: Hi Mike, First of all, Wow what an interesting read, thanks for sharing some of the history and your experiences with the 105. A second thanks for uploading the manual, which I found to be a great read, as with most old test & measurement product

Re: [time-nuts] ``direct'' RS-232 vs. RS-232 via USB vs. PPS decoding cards

Yo Ruslan! On Mon, 13 Feb 2017 11:07:49 -0500 Ruslan Nabioullin wrote: > Hi, generally speaking, what are the performance differences between > the following: 1. direct RS-232 (i.e., what I believe is a standard > PCI card offering RS-232---essentially UARTs interfaced

Re: [time-nuts] Vintage Frequency Measurement

The BC-221 was the backbone of WW2 communications. How else were all those sloppy BC-348's and AR-13's set to the called-for frequencies? Same for shipboard. Don On 2017-02-13 13:05, Brooke Clarke wrote: Hi Bob: The BC-221 is usually referred to as either a Frequency Meter or a Heterodyne

Re: [time-nuts] Vintage Frequency Measurement

Hi Bob: The BC-221 is usually referred to as either a Frequency Meter or a Heterodyne Frequency Meter. -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html Original Message Hi Ok, so how does that make a BC-221 a wave meter?

[time-nuts] ``direct'' RS-232 vs. RS-232 via USB vs. PPS decoding cards

Hi, generally speaking, what are the performance differences between the following: 1. direct RS-232 (i.e., what I believe is a standard PCI card offering RS-232---essentially UARTs interfaced more-or-less directly to the PCI bus); 2. RS-232 via USB; 3. PPS decoding PCI cards (which might also

Re: [time-nuts] Vintage Frequency Measurement

Hi: Here's a GR 358 wavemeter from the 1920s. Someone noticed the GR logo after I made the web page that led to it's identification. Hence the generic page URL. http://www.prc68.com/I/Wavemeter.html Covers 14 to 220 Meters (21 to 1 MHz) in four bands selected by which inductor you connect to

Re: [time-nuts] Vintage Frequency Measurement

On Sun, Feb 12, 2017 at 8:39 AM, Dan Rae wrote: > On 2/11/2017 10:08 PM, Scott Stobbe wrote: > >> I was inspired recently coming across a Lampkin 105 frequency meter, as to >> how frequency measurement was done before counters. >> >> Certainly zero-beating a dial calibrated

Re: [time-nuts] how many seconds out does GPS discipline being to improve Rubidium stability?

Surely you just loop it through two counters using a T-piece, with those counters set to high impedance input, then only terminate the final one? Peter On 12 February 2017 at 18:16, gkk gb wrote: > That is an interesting suggestion (thanks), and would indeed work