Author Topic: 1GHz Freq Counter  (Read 6317 times)

diba

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1GHz Freq Counter
« on: September 30, 2012, 10:35:54 pm »
Hi,
I built A project 1 GHz Counter but i have problem as an Err appear on the display and if I remove SAB6456 Ic the zero will display and if i touch R2 pin a different figure be showed, what the issue? please 

Jan

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Re: 1GHz Freq Counter
« Reply #1 on: October 01, 2012, 09:13:55 am »
It probably works ok. The prescaller IC oscillates with no signal connected (see its datasheet). If it oscillates above 1 GHz, the "Err" is indicated. Feed a correct signal.

Hartmut

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Re: 1GHz Freq Counter
« Reply #2 on: November 24, 2012, 02:06:56 pm »
Hello,
I translate my text through Google, because my English is very bad.
I built the counter and have the following problem. The prescaler, a SIP U664B divides the frequency by 64 clean 446MHz input has on the PIN3 16F84 a frequency of 6.9668 MHz, so OK.
The indicator on the display is 1445 but without Dp. At a frequency of about 108MHz is on the display 4817, and the input frequency in the PIC is 1.6875MHz. Without prescaler, the display shows the 00th What is wrong and who can help me?

Thanks Hartmut

Jan

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Re: 1GHz Freq Counter
« Reply #3 on: November 24, 2012, 02:34:04 pm »
The input signal frequency needs to be divided by 256.
The DP is hard-wired so you have probably a mistake in the display connection.

Hartmut

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Re: 1GHz Freq Counter
« Reply #4 on: November 24, 2012, 05:15:25 pm »
Thanks for the quick reply! I'll check everything again and sign up again. Thank you!
There may be at my age - I'm 63 (lol)

Hartmut

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Re: 1GHz Freq Counter
« Reply #5 on: November 24, 2012, 06:00:26 pm »
I have checked my counter: broken prescaler, not divides by 256
dp-led defective in the display.

Jan

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Re: 1GHz Freq Counter
« Reply #6 on: November 24, 2012, 07:28:21 pm »
The U664B divides by 64 but you need a prescaler of 256 (like SAB6456 or U813BS).

Alternatively you may use U664B but there must be another divider by 4 present on the PIC input (this may be based on some 74xx logic circuit). This will result in total division by 256.

Hartmut

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Re: 1GHz Freq Counter
« Reply #7 on: November 29, 2012, 06:22:31 pm »
Hello!

Thanks for the advice. I have bought a U813 BS SI and now the counter is working properly. I need to change the display still does not work because of the DP. Thanks again for the instructions. I wish all users a Merry Christmas.

Hartmut