Enabling MEAN with 100 pts under Statistics should give an additional digit but will take a few minutes for a reading with longer gate times.
Keith Keith On Mon, Dec 8, 2014 at 3:07 PM, Bob Camp <[email protected]> wrote: > HI > > At a 1 second gate, your 5335 is good to about 1 ppb. (1x10^-9). A TCXO > based GPSDO should be good to 10X that level. An OCXO based unit should be > good to 100X that level. If you extend the counter’s gate time, the 5335 > will overflow fairly quickly. Up to the point it does, it’s accuracy will > improve directly with the gate time. Once it overflows, you can correct the > result, but it is messy. > > Bob > > > On Dec 8, 2014, at 2:07 PM, Byron Hayes Jr <[email protected]> wrote: > > > > Time-Nuts Group, > > > > I thought some of you might be interested in my experience with the > 10MHz LTE-Lite. > > > > The 10MHz LTE-Lite arrived about a week ago. I was not ready to make a > permanent installation, I wanted it portable and I wanted to get started > quickly. I am hobbyist interested mainly in the HF spectrum. So I decided > to operate the LTE-Lite inside the Priority Mail box, which was pretty much > intact. I cut a 5" X 8" piece of corrugated cardboard, mounted the unit on > it with two doublestick pads, and put the cardboard with the unit into the > Priority Mail box. I cut a hole in the top of the box so I could see the > LEDs, and cut three small holes in the side, one for the USB cable, one for > the antenna wire and one for the 10 MHz output. I attached the USB cable, > antenna wire and 10 MHz output cable to the unit and ran them out of the > box through the holes. I had an operating Lenovo X220 Windows 7 computer > near to the box, so I plugged the USB cable into the computer (I did not > try to get or use any software on the computer to decipher any messages > from the LTE-Lite). I was in a > n upstairs North facing bedroom (in the Los Angeles area) so I put the > antenna on a nearby windowsill. I hooked the 10MHz output to the channel 1 > (Hi Z) input of my Tektronix 222A osciloscope, with the trigger on channel > 1. > > > > When power was applied through the USB line, the LEDs seemed to light > normally. Within a couple of hours the lock LED was on, but the > oscilloscope was showing noise, not a meaningful output. I let the whole > thing sit overnight, and the next day an apparent 10 MHz trace was on the > screen. It was not a sine wave, and not a square wave, but something in > between. > > > > I had a small Rb unit, an Efratom 10 MHz FRS-C built into a TM-500 > plug-in. I set that up and let it warm up and lock. I connected the Rb > output to channel 2 of the 222A and got that trace on the screen. It was a > sine wave basically in lock step with the LTE-Lite trace. Over a few hours > one could see slight relative movement, but very slight. What next? > > > > I had a couple of HP 5300 series frequency counters, one a 5300B display > with Option 1 (Hi-Stability time base) and a 5308B lower unit, and the > other a plain 5300B display with a 5303B Option 1 (Hi-Stability time base) > lower unit. I give both time to warm up. I put a "T" in the LTE-Lite > output line and another "T" in the Rb output line, and connected coax from > the Ts to the HiZ input of each frequency counter. After they settled > down, the counter connected to the LTE-Lite read 10000008 and the counter > connected to the Rb read 10000002. So, after a while, I reversed the leads > to the counters, and the counter connected to the LTE-Lite read 10000002 > and the one conntected to the Rb read 10000008. Those readings have been > consistent for several days. That indicated to me that the LTE-Lite and > the Rb were both outputing essentially the same frequency, but the counters > were a bit off (I had never calibrated these counters, since I wasn't sure > of the accuracy of the Rb unit). But, > I felt like the proverbial man with two watches. > > > > So, I brought out "Big Gonzo", a HP 5335A counter with Option 010 > (Hi-Stability time base) I purchased on eBay about six months ago but had > never fired up. It came up OK and I hooked it to the LTE-Lite output. It > initially read 10000028, but I gave it a couple of hours to warm up the > oscillator oven and stabilize. By then, the reading had settled to 10 000 > 000. Now I switched cables and hooked the Rb to the 5335A, and it read 10 > 000 000. I hooked the LTE-Lite to channel A of the 5335A and the Rb to > channel B of the 5335A, and set the counter to "ratio". When it settled, > the counter read 1.000 000 indicating that the two outputs were the same > frequency, at least to six decimals. Apparently the 5335A is "right on". > > > > I conclude that both the LTE-Lite and the Rb are outputting a 10000000 > MHz signal. I'm not sure of the accuracy beyond that. They are probably > both accurate enough for my purposes for calibrating other test equipment, > receivers and transmitters operating in the HF spectrum. > > > > I would be interested in any comments or suggestions from other list > members. > > > > Byron WA6ATN _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
