[time-nuts] PRS10 Lamp Module Needed

Vasco, As Brooke said it is unlikely there are spare PRS10 lamp modules found outside the manufacturer. The probable reason is that when the PRS10 units are assembled certain adjustments to the firmware are necessary such as the starting level and final bias of the FET oscillator transistor.

[time-nuts] FE5680 Versions

Can one determine whether a given FE5680 is of the analog or digital control type without opening it? Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the

[time-nuts] FEI-5660 Rubidium Oscillator

Recently I happened across an eBay listing for an Antelope Audio Isochrome, a device that apparently packages an SRI-PRS10 rubidium oscillator and distribution amplifier in a box and sells to audiophiles for a price in the $10K range. For the fun of it I searched eBay for Audio Isochrome

[time-nuts] Off-Topic Question -- German Composition Resistors

While tracing out a PC board from an instrument manufactured in Germany, I quickly discovered the color code on 1/4-watt composition resistors is not the same as that commonly used in the US For example, I would measure about 10,000-ohms across a presumably good resistor that appeared to be

[time-nuts] Off-Topic Question -- German Composition Resistors

My sincere thanks to those who responded to my request for help. The link to a chart provided by Ernie allowed me to recognize I was looking at five-stripe resistors with three significant figure stripes followed by a multiplier stripe and spaced a little further away a red stripe

Re: [time-nuts] Need to measure frequencies of two sources simultaneously

If the two frequencies are reasonably separate, an EIP counter such as the 54x or 57x series could be programmed to select the desired frequency. This could be orchestrated through the counter's GPIB interface, or alternately, two counters could be used -- one for each frequency. Bruce,

[time-nuts] RB video

I believe the subject video does a nice job introducing viewers to the construction and potential of EXTRON's extensive of NTSC video equipment housed in nice, reusable cabinets. The cabinets that I am familiar with have slide-in front and back panels of 1/16-inch aluminum that can easily

[time-nuts] Distribution Amp for Thunderbolt and David Partridge's Divider Box

A year or so ago I modified an Extron ADA 6 300MX TV distribution amplifier to house one of David Partridge's divider boards along with a 1 MHz sine-wave filter and a 10 MHz to 100 MHz multiplier after Luciano Paramithiotti's design. I use the rear BNC connectors to distribute 1, 10,

[time-nuts] WWVB Clocks don't sync anymore (revisited)

Our favorite La Crosse bedroom projection clock stopped synchronizing about the time WWVB implemented phase-modulation. However, even unlocked, it keeps pretty accurate time. When Daylight time comes or goes, in the spring and fall, I have to take the clock out on the deck and remove and

Re: [time-nuts] Repair of PRS10 Lamp Assembly

I am afraid the PRS-10 lamp starting algorithm is a little involved. I believe that once the lamp temperature is in the starting range, the microprocessor ramps up the drain and possibly gate voltage of the heating oscillator FET until the bulb strikes as evidenced by a DC signal at the

[time-nuts] Subject: Re: Don't use cheap cables -- a cautionary tale

I would like to add to Bob Camp's comment about twisted pair. In the past I used to provide one-turn resonant loop antennas for AM broadcasters who needed to monitor signals from their transmitters at studio facilities in electrically noisy urban buildings. The three-foot diameter

[time-nuts] Thunderbolt Distribution Amplifier Needed

Chris, I was able to mount my David Partridge divider board inside an Extron ADA 6 300MX television distribution amplifier along with a 1 MHz sine wave filter and a 10 MHz to 100 MHz multiplier. On the front panel is a selector switch for selecting the division ratio, BNC jacks for this

[time-nuts] Fe-5680A -vs- LPRO

Is anyone prepared to comment on the relative performance of the FE-5680A compared with the LPROs? Bruce Hunter, KG6OJI ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and

[time-nuts] Fe-5680A -vs- LPRO

Bob, WOW! Thanks for the very comprehensive report. Bruce, KG6OJI ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.

[time-nuts] Spectracom 8170 - SWCC clock

Jim, If your Western Union clock is similar to the type used in broadcasting, you might want a setting pulse that starts at 59:59 and ends at 00:00 . The reason is that at 59:59 the magnet pulls the second hand to the 12 o'clock position and releases it on the hour. The one-second

[time-nuts] Symmetricom 2700 Time Source

I removed the SRS PRS-10 oscillator from my unit for examination. The 1PPS output appears on Pin #5 (See page 19 of the manual) and is not connected to the 2700. It appears the 2700 does not rely on the PRS-10 alone for timing information; it tracks and aggregates available sources.

[time-nuts] Symmetricom 2700 Time Source

Following a recent posting from a group member advising that Symmetricom 2700 CDMA Primary Reference Sources contain SRS PRS-10 rubidium oscillators, I was able to buy one of these units at reasonable cost from the usual auction source. After removing the PRS-10 oscillator and while

[time-nuts] OT - MIT Radiation Lab Series

This discussion about the Radiation Laboratory series reminded me that in looking at a book on high vacuum techniques that I purchased in the late 1950's, I was surprised to see it was part of a series on the wartime development of nuclear energy written at the end of WW-II in a similar

[time-nuts] BNC Question

An Amphenol document discussing the mating compatibility of their 50-ohm and 75-ohm BNC connectors can be found here _http://www.amphenolrf.com/products/bnc.asp?N=0sid=46B11E806D75617F_ (http://www.amphenolrf.com/products/bnc.asp?N=0sid=46B11E806D75617F) . Bruce, KG6OJI

[time-nuts] BNC Question

Interestingly, 50 and 75-ohm BNC connectors have the same pin/shell dimensions and properly couple together. For more information go to _http://www.cliftonlaboratories.com/august_2007.htm_ (http://www.cliftonlaboratories.com/august_2007.htm) and scroll down to the 02 August 2007 entry.

[time-nuts] Partridge Divider Board and 10 MHz Distribution Amplifier Enclosure -- an Idea

While admiring my newly received divider board from David Partridge and thinking about a suitable enclosure for its use on my bench, I happened to look at an Extron ADA3 80 video distribution amplifier that I acquired after suggestions from KO4BB. These enclosures are mechanically sturdy

[time-nuts] Update -- Comparing 10 MHz Oscillators at 10 GHz

Thanks to some help from Joe Ruggieri, I finally managed to get a pair of 10.000 GHz microwave brick oscillators phase-locked to 100 MHz inputs. These require an input of about 0 dBm at 100 MHz and have an output of about + 13 dBm at 10 GHz. To gauge whether or not loop noise would

[time-nuts] Garage built Rubidium standard

The Garage-Built Rubidium Standard discussion brought to mind an experimental setup in a physics lab at U. C. Berkeley years ago. It was one of a number of elective experiments for the laboratory section of a Modern Physics course. The objective was probably to demonstrate Zeeman line

[time-nuts] Comparing 10 MHz Oscillators at 10 GHz

Luciano Paramithiotti's January 1 post about his 10-to-100 MHz multiplier project reminded me of past musings about using two 10GHz, phase-locked oscillators to compare the 10MHz outputs of my T-bolt and LPRO so I could quickly adjust the latter by observing the mixed 10 GHz signals with a

[time-nuts] Question about Russian PC-Series Circular Military Connectors

I would like to take advantage of this group's worldwide constituency and ask a slightly off-topic question about the contact numbering scheme for Russian PC-series circular connectors. I am trying to trace out the wiring of a Russian manufactured radiometer with these connectors.

[time-nuts] Greyfox Surplus box

Today, while at HSC Electronics, an electronics surplus store in Rhonert park, CA, I picked up a GreyFox R1056 distribution box that looked like it had possibilities either as a distribution amplifier for 10 MHz or for GPS signals. But to my surprise, I could not find any information about

[time-nuts] Aside about Triangle Waveforms

A widely used WW-II aircraft radio altimeter used a triangular waveform to FM modulate a 400 MHz oscillator, employing a mechanical variable capacitor constructed similar to a permanent-magnet loudspeaker. To get the capacitor's diaphragm to reverse accurately, at the positive peak of the

[time-nuts] Conducting Bench Top Material

My electronic bench is an old commercial one made with steel stampings and a steel top covered with Masonite. The Masonite is still in fair condition. Although over the years the non-conductive top has been an asset in avoiding short circuits, etc., I am concerned about static discharges

[time-nuts] 4 KV Power Supply Requirements

Many decades ago, before high-voltage diodes were available, I constructed 4 KV, 50 ma klystron power supplies using strings of 600-volt PIV, metal-case diodes mounted on commercial Bakelite terminal boards. After soldering, I sprayed the entire board heavily with Krylon high-voltage spray

Re: [time-nuts] 4KV Power Supply Recommendations

Slightly off topic -- but perhaps suggestive: A couple of years ago I needed to re-train some nocturnal raccoons who were toppling our garbage can. I purchased an inexpensive and very compact fence charger at a farm supply. Opening the lightweight unit out of curiosity, I found that it

[time-nuts] Question about Firmware for EIP Counters

Is anyone on the list familiar with the firmware for EIP 578 or 548 series counters? I have a favorite 578 counter, with power measuring option, that I have owned for years. All of this time I have wished it had the Frequency Extension option. Recently I bought a mechanically-damaged 578

[time-nuts] Multiplying 10 MHz to 100 MHz

In an earlier post I mentioned that I had been searching on-line for ideas to multiply a 10 MHz signal to 100 MHz. I would like to multiply the 10 MHz outputs of an LPRO and a Thunderbolt GPS to feed to 10 GHz phase-locked microwave sources so their outputs can be fed to a mixer for

[time-nuts] LPRO-GPSDO

In searching on-line for ways to construct a 10 MHz to 100 MHz multiplier, I came across an interesting product offered by Silicon Forest Solutions _http://www.TenMHz.com_ (http://www.TenMHz.com) . Their LPRO-GPSDO incorporates a refurbished LPRO rubidium oscillator, disciplined by a GPS

[time-nuts] Invariance

If from relativity theory time is NOT considered invariant, would frequency (in terms of the output of a cesium standard or hydrogen maser) be considered invariant? Bruce Hunter ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] GPS Antenna and Lightning (Bruce Hunter)

A 6 to 30 MHz Voice of America receiving site in North Carolina had an interesting experience when vacuum-tube antenna RF distribution amplifiers were replaced with solid-state units. At first, frequent damage occurred to the input stages of the solid-state amplifiers, whereas few problems

[time-nuts] GPS Antenna Voltage-Dropping

I bought a 3.6-V Trimble Bullet GPS antenna on ePay and wish to use it with my T-bolt. Rather than try to internally modify the T-bolt to provide a 3.6-V antenna feed, I decided to try to build an in-line dropping adapter. I seriesed two Si diodes inside a 100 pf tubular ceramic capacitor

[time-nuts] Connecting Wireless Adapter to a TBolt

Thanks to all for your suggestions. Bruce Hunter **It's raining cats and dogs -- Come to PawNation, a place where pets rule! (http://www.pawnation.com/?ncid=emlcntnew0008) ___ time-nuts mailing list -- time-nuts@febo.com To

[time-nuts] Wireless Adapter for an TBolt

Has anyone coupled a wireless adapter to a TBolt so that it can be accessed from a computer in another room. This would be convenient for me if it could be made to work. Bruce Hunter **It's raining cats and dogs -- Come to PawNation, a place where pets rule!

[time-nuts] Subject: Thunderbolt Stability and Ambient Temperature

This interesting discussion of heat conduction by members of the electronics community brings to mind that in the 1870's, Joseph Fourier, while analyzing the waveform of heat propagating around a metal ring, developed the elegant method of Fourier Analysis. If you have not seen his work

[time-nuts] Vectron Labs OCXOs Pin-out

Steve, In my experience Vectron has not been able/willing to provide info on earlier oscillators. I acquired a 229-7730-9, 100 MHz unit and with an ohmmeter decided the pin connections seemed to match the diagram shown for the current CO-706 series. The question then was whether the

[time-nuts] Upgrade for LPRO 10 MHz Oscillator?

Has anyone upgraded the LPRO oscillator by out-boarding a suitable OCXO unit? Bruce Hunter **Know Your Numbers: Get tips and tools to help you improve your credit score. (http://www.walletpop.com/credit/credit-reports?ncid=emlcntuswall0002)

Re: [time-nuts] time-nuts Digest, Vol 52, Issue 74

In a message dated 11/26/2008 12:29:32 P.M. Pacific Standard Time, [EMAIL PROTECTED] writes: [EMAIL PROTECTED] Tom, I would be interested in one of the Thunderbolt units if you are able to do another group buy. Best regards, Bruce, KG6OJI **Finally, one site has it all:

[time-nuts] Checking the Frequency of a Rubidium Oscillator

Thanks to all that explained the hopelessness of measuring GPS satellite transmission frequencies directly with a simple counter. I should have known better, but probably have been retired too long. Bruce, KG6OJI **Get movies delivered to your mailbox. One month free from

[time-nuts] Checking the Frequency of a Rubidium Oscillator

I have an EIP Model 548 counter with a YIG-tuned front end that can be programmed to scan over narrow frequency ranges. By feeding the rubidium oscillator under test into the 10 MHz clock input of the counter, is there any reasonably simple way to directly measure the frequency of a GPS