10 MHz Everywhere! - Page 1
Forum section: electronics / general

author: xrunner
author_rank: Super Contributor
timestamp: April 07, 2017, 06:36:11 pm
content: TheSteve started this ...Quote from: TheSteve on April 07, 2017, 06:28:45 amIt does seem to be everywhere TheSteve, it's at my house too. In fact it's all over the placehere.Is it at anyone else's house?

author: slurry
author_rank: Regular Contributor
timestamp: April 07, 2017, 06:43:04 pm
content: It's in my house too, strange... hmmm...I run a FE-xxxx Rubidium and usually a re-purposed video distribution amplifier but now a BG7TBL distribution amplifier is used, i'm not really a time-nut so i keep it simple...for now

author: TheSteve
author_rank: Unknown
timestamp: April 07, 2017, 06:59:18 pm
content: Quote from: xrunner on April 07, 2017, 06:36:11 pmClearly my distribution amplifier is working extremely well.

author: JPortici
author_rank: Super Contributor
timestamp: April 07, 2017, 08:45:34 pm
content: I don't trust that 10.000000 (muhuahahaha)

author: xrunner
author_rank: Super Contributor
timestamp: April 07, 2017, 10:14:36 pm
content: Quote from: JPortici on April 07, 2017, 08:45:34 pmOh man, now I can't believe you don't trust that.How can I convince you?

author: Brumby
author_rank: Unknown
timestamp: April 08, 2017, 03:25:18 am
content: That is an elegant piece of gear.

author: awallin
author_rank: Frequent Contributor
timestamp: April 08, 2017, 08:44:44 am
content: Quote from: Brumby on April 08, 2017, 03:25:18 amDon't turn it on - take it apart

author: Brumby
author_rank: Unknown
timestamp: April 08, 2017, 08:51:33 am
content: If you must .... but DON'T scratch the case!

author: DimitriP
author_rank: Super Contributor
timestamp: April 08, 2017, 09:58:31 am
content: Quote from: xrunner on April 07, 2017, 10:14:36 pmAdd more 000

author: TiN
author_rank: Super Contributor
timestamp: April 08, 2017, 11:16:24 am
content: Meh, time-nuts... I don't even monitor my Rb...

author: xrunner
author_rank: Super Contributor
timestamp: April 08, 2017, 03:12:12 pm
content: Quote from: DimitriP on April 08, 2017, 09:58:31 amHehehe - How many? I'll never be able to add enough to satisfy you - I know how this game goes.

author: tszaboo
author_rank: Super Contributor
timestamp: April 08, 2017, 04:48:39 pm
content: So, that means, if you connect the 10 MHz on the front, and on the back of a timer counter, than it will be 10 MHz on the screen?

author: PA0PBZ
author_rank: Super Contributor
timestamp: April 08, 2017, 05:01:54 pm
content: Quote from: NANDBlog on April 08, 2017, 04:48:39 pmLet me tell you a little secret: It doesn't even have to be 10 MHz

author: TheSteve
author_rank: Unknown
timestamp: April 08, 2017, 05:14:10 pm
content: Quote from: awallin on April 08, 2017, 08:44:44 amAlready done! I had to see the inside.

author: bingo600
author_rank: Super Contributor
timestamp: April 08, 2017, 05:40:54 pm
content: That's not an "Everywhere Box"Thisis an "Everywhere Box"- 8 x 5 (40) outputs - I got mine from KJDS.https://www.eevblog.com/forum/testgear/fun-with-a-racal-9480-with-ocxo-40-10mhz-outputs-(8x-5-chan)/msg653659/#msg653659http://www.ebay.com/itm/Racal-9480-10-04B-Time-and-frequency-mainframe-/401010554495Congrats Steve - I bet it has nice specs./Bingo

author: TheSteve
author_rank: Unknown
timestamp: April 08, 2017, 05:46:07 pm
content: It does look pretty - but does yours accept two inputs and auto fail over to the backup input, while also accepting alarm inputs and generating alarm outputs?

author: bingo600
author_rank: Super Contributor
timestamp: April 08, 2017, 05:54:36 pm
content: It actually have a built-in ocxo (or RB) , that it switches to.If the primary input fails (is undetected)And it has alarms etc too ... , yours seems like it's a "next gen" dist-amp though.I got it because i ran out of chans. on my old distamp , now i have enough/Bingo

author: TheSteve
author_rank: Unknown
timestamp: April 08, 2017, 06:06:41 pm
content: Mine is still from the HP era of course. I did some basic testing and its performance seems better then anything I own can measure.It can have an OCXO fitted internally and will fail to it. I will see if I can get some good pics later. It does seem rather entertaining that a 10 MHz distribution amp would have firmware, a processor, ram, and it communicate via SCPI. I admit I have lusted after one for quite some time, I've made several lowball best offers on them over the last year or two. One was finally accepted.

author: Red Squirrel
author_rank: Super Contributor
timestamp: April 08, 2017, 09:04:29 pm
content: Need one of these too now:http://www.ebay.ca/itm/Symmetricom-OT-21-Officetime-Multiplexer-25413150-411-0-/272452367547?hash=item3f6f6d34bb:g:QAwAAOSwcLxYLOIzAnd GPS antenna.That's a different kind of "clock" though.Those GPS antennas also double as lightning rod, my coworker who was in our building when it got hit knows all about that.I don't know too much about this stuff, just that it's used to sync up communication stuff, but I think they also have an NTP server built in. Why use time.gov as a time source when you can be your own time source!

author: TheSteve
author_rank: Unknown
timestamp: April 11, 2017, 04:38:07 am
content: The 58502A got its own shelf.Seems to be bang on....

author: tszaboo
author_rank: Super Contributor
timestamp: April 11, 2017, 09:22:18 am
content: Quote from: PA0PBZ on April 08, 2017, 05:01:54 pmI dont understand time nuts. They can create voltage references, or very accurate currents, but they waste their time on time...

author: Berni
author_rank: Super Contributor
timestamp: April 11, 2017, 01:01:53 pm
content: Quote from: NANDBlog on April 11, 2017, 09:22:18 amWell at least its a slightly easier hobby than being a volt nut. You can use GPS clocks to verify long term drift of your oscillators. No such thing for checking if your HP 3458A is drifting.

author: Harb
author_rank: Regular Contributor
timestamp: April 11, 2017, 01:08:22 pm
content: I just use a big VDA....I think it has 100 or so outputs.....10 on each euro card.

author: edpalmer42
author_rank: Super Contributor
timestamp: April 11, 2017, 04:52:10 pm
content: Quote from: Harb on April 11, 2017, 01:08:22 pmOne 'trap for young players' when you convert a 75 ohm Video Distribution Amp to 50 ohms is total load. I use a VDA that uses an Analog Devices amplifier. It can handle 8 75 ohm outputs but only 5 50 ohm outputs. It's not a big problem because you can daisy chain multiple inputs together. But it's something to keep in mind.Ed

author: TheSteve
author_rank: Unknown
timestamp: April 11, 2017, 05:38:49 pm
content: I used a modified VDA previously and the output quality was crap. Obviously they vary in quality like everything else, the one I chose was clearly junk.

author: Harb
author_rank: Regular Contributor
timestamp: April 12, 2017, 02:07:50 am
content: Quote from: edpalmer42 on April 11, 2017, 04:52:10 pmYeah Mine had heaps and heaps of headroom so after the conversion it still drives all the outputs fine.......I don't use all of them though......I daisy chained all the cards together and just spread the load across all of them

author: DaJMasta
author_rank: Super Contributor
timestamp: April 12, 2017, 04:21:03 pm
content: I've been considering a distribution amp for a bit now, but I stumbled on a ESE ES-247E for about $30 on ebay. It's a 75 ohm 4x6 amp (4 banks of 6 outputs), but it's got the same form factor and look as their 50 ohm variant (which is several times the price on ebay).Well I bought one and cracked it open - uses an OPA603 on each channel, with a 15 ohm series resistor to each of the 6 outputs, very simple design overall, and the input has two connectors, one for the signal and one for a terminator. Waiting on a set of 4 50 ohm terminators and I'll see if the opamp can handle.... but the resistors are easy-access and the chips are even socketed if they're not up to the task. Seems like a great little unit to try and convert over.