Re: [time-nuts] ACAM GP22 Chip

Hi If you head down to your local big box store, they will happily sell you a thousand foot spool of RG-6 coax for next to nothing. If their prices are still to high, the auction sites will sell it for even less. It has a 75 ohm impedance and a bandwidth of several GHz. The rather convent

Re: [time-nuts] ACAM GP22 Chip

If the goal is to create two signals consistently spaced near 70us apart why not use a good, fast 8-bit serial-in, parallel out shift register, clocked cleanly at 100kHz? Using the outputs from stages 1 and 8 would result in a 70us delay between signals. The data in would be fed 100KHz divided

Re: [time-nuts] Trimble Thunderbolt E frequency pulling

Al, Thanks for the good idea, that would certainly have saved me a bit of work:-), but the switch box inserted in the coax line with the counter input set to high impedance performs the same function, straight through connection with the option to switch in a 50 ohm shunt resistor, and it's

Re: [time-nuts] ACAM GP22 Chip

th.allge...@gmail.com said: > I should say from the start that I am new to time and frequency measurements > and not even an electronics engineer – but then I have been exposed to > high-precision electronics for the last 25 years hence have picked up some > dangerous degree of half-knowledge.

Re: [time-nuts] Trimble Thunderbolt E frequency pulling

Nigel, Set your counter to high impedance. Then install a T connector on the input. Then you can install or remove a 50 ohm terminator on the T while plotting the results. Then you can see how fast the frequency shift is depending on the load. AL, k9si Switching the impedance at the

Re: [time-nuts] ACAM GP22 Chip

Moin, On Tue, 24 Nov 2015 14:04:32 - "Thomas Allgeier" wrote: > We want to use this chip to measure the period of a square wave, of > around 13 kHz i.e. in the 70 µs range. As the application is potentially > high-accuracy we need to know the period to within 1 ns or

[time-nuts] ACAM GP22 Chip

Hello, I have an ACAM GP22 TDC chip and evaluation board which I am looking at for “work” purposes – I work for a company active in the weighing and force measurement world. I should say from the start that I am new to time and frequency measurements and not even an electronics engineer –

Re: [time-nuts] PRS10 Heatsink Temperature

> Le 24 nov. 2015 à 01:33, Charles Steinmetz a écrit : > > David wrote: > >> I plan to add a small temperature controlled fan to limit the heatsink >> temperature. Can anyone recommend a suitable setpoint for the heatsink? > > An SRS engineer once told me to keep the

Re: [time-nuts] Trimble Thunderbolt E frequency pulling.

My bet is interaction of the load current and power supply with the EFC and/or OCXO - Well, I haven't started probing the hardware yet, I was hoping I might get some confirmation first as to whether what I I'm seeing is an anomaly for this one or just par for the course with the

Re: [time-nuts] PRS10 Heatsink Temperature

The LPRO data manual has a graph of MTBF and operating temperature. The lower the temperature, the longer it lives. I would choose a temperature so low that for maybe 5% of the time the fan control would not hold it down but let it run 1 or 2 degrees high. It depends on how you value its life and

Re: [time-nuts] ACAM GP22 Chip

Thomas Welcome to the group. I am sure others will comment. Many of us have a very wide range of experience and expertise so you should feel comfortable with any question. To the coax delay question. You are not pushing the limits. But its important to understand the impacts of such long lines.

Re: [time-nuts] ACAM GP22 Chip

my 2 cents: 1) hack a RC delay + comparator (isolate well the R and C for temp variations) 2) use a proper delay line (can be bought at digikey/mouser/etc) Daniel Em 24/11/2015 12:04, Thomas Allgeier escreveu: Hello, I have an ACAM GP22 TDC chip and evaluation board which I am looking