Page 1 of 1

External Time Base T5829A for Quantar

Posted: Sat Jun 17, 2017 9:29 am
by abrigno1
Planning to use MOTO External Time Base T5829A on Quantar 900 MHz for Amateur. Have issue. Time base is showing non-sine wave output with voltage of little over 6 V into 1 meg input on high quality Lecroy scope.

Quantar docs show external voltage should be 1.0 V(RMS) +/- 0.5V

Is this an issue? What output voltage should be on output terminals of the T5829A.

Also, does anyone have any docs on T5829A. It was donated to our ham club but we have no documentation.

Any help would be appreciated

Re: External Time Base T5829A for Quantar

Posted: Sat Jun 17, 2017 4:40 pm
by Astro Spectra
Well for starters V peek-to-peek is roughly 2.8 x V RMS for a sine wave. Also you're measuring the open circuit voltage. If it comes from a 50 or 75 ohm source, it will be half what you measure now when terminated in 50 or 75 ohms.

So if you are measuring 6 volts peek-to-peek and the source is intended for the Quantar then it probably about right. Use a BNC T and either run it into the Quantar or if you're worried a 50 ohm load and measure again.

Re: External Time Base T5829A for Quantar

Posted: Sat Jun 17, 2017 5:58 pm
by abrigno1
Closer than I thought. Still taking readings. On a quick check what I saw with a 50 ohm jumper was about 5.2 V RMS. Still little high.

Repeater arrived this afternoon so I will be testing and measuring with actual repeater.

Really appreciate answer. Want to make sure I don't damage repeater.

Re: External Time Base T5829A for Quantar

Posted: Sat Jul 01, 2017 2:49 pm
by fineshot1
The Trak 9100 is the typical and usual time source for most of todays Motorola trunk systems
with Quantars. IIRC they use a 5 or 10Mhz 1VRMS P-P sinwave. Click on the url below.

http://www.simulcastsolutions.com/userf ... ak9100.pdf

Re: External Time Base T5829A for Quantar

Posted: Sat Jul 01, 2017 4:44 pm
by abrigno1
I have a 5829 that is working. Issue is voltage is about 3.5V RMS vs book value of 1 +_>0.5 Seems to be working fine.

Re: External Time Base T5829A for Quantar

Posted: Sun Jul 02, 2017 4:50 am
by Jim202
abrigno1 wrote:I have a 5829 that is working. Issue is voltage is about 3.5V RMS vs book value of 1 +_>0.5 Seems to be working fine.


If your that concerned, then add an in line 3 db pad. That should bring the voltage down to about 1.5 volts.

Jim

Re: External Time Base T5829A for Quantar

Posted: Sun Jul 02, 2017 5:19 am
by abrigno1
Voltage divider would work equally well for 5MHz. One issue is the 5829 has 8 BNC connections. I was wondering if there was some malfunction as I don't have the specs for it. Also could the output be reset to some lower value.

I would like to know more about the 5829A. It is one of the very few pieces of equipment that I don't have a manual for.

Re: External Time Base T5829A for Quantar

Posted: Sat Jan 20, 2018 7:57 am
by fineshot1
Sorry this reply took so long - I looked over some of these units for sale on ebay and also
noticed the thread below. Apparently this unit requires either a stable or both 10Mhz frequency
and 1PPS standard inputs in order to output 8 5Mhz stable outputs. That is all i could find on the
T5829A. By itself I doubt it would be useful to you in your quest. Hope this helps you find out more.

https://www.febo.com/pipermail/time-nut ... 04928.html

Re: External Time Base T5829A for Quantar

Posted: Mon Jan 22, 2018 12:07 pm
by fineshot1
fineshot1 wrote:Sorry this reply took so long - I looked over some of these units for sale on ebay and also
noticed the thread below. Apparently this unit requires either a stable or both 10Mhz frequency
and 1PPS standard inputs in order to output 8 5Mhz stable outputs. That is all i could find on the
T5829A. By itself I doubt it would be useful to you in your quest. Hope this helps you find out more.

https://www.febo.com/pipermail/time-nut ... 04928.html
NOTE: Sorry for the bad url above - don't know how that keeps happening - see below

https://www.febo.com/pipermail/time-nut ... 04928.html