Re: [time-nuts] Z3801A ThunderBolt USING SAME ANTENNA?
Will I have a problem connecting the thunderbolt to the smartsplitter using LRM400 50 ohm cable? Try whatever cable you have handy. It's not likely to break anything. I'm assuming you have some way to monitor your Thunderbolt and see if it's working well enough. -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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.
Re: [time-nuts] Z3801A ThunderBolt USING SAME ANTENNA?
From: Bruce Griffiths [EMAIL PROTECTED] Subject: Re: [time-nuts] Z3801A ThunderBolt USING SAME ANTENNA? Date: Wed, 09 Jul 2008 13:54:39 +1200 Message-ID: [EMAIL PROTECTED] Bruce, The 50 ohm BNC connector is rated up to 4GHz, the 75 ohm version to 2GHz. Modern 75 Ohm BNC and cable is rated for 4.5 GHz. Used for 2.97 Gb/s HD-SDI. See Trumpeter and Belden cables. The F connector performance degrades above 1GHz but is still useful to several GHz. Both originated in the early 1950's. The Thunderbolt should work well with 50 ohm cable as its far from a precision match to either 50 or 75 ohm cable. Cheers, Magnus ___ 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] Z3801A ThunderBolt USING SAME ANTENNA?
Hi, I am trying to set up a Z3801A and a ThunderBolt to operate off of one symmetricom 58532A antenna using a symmetricom 4-port smartsplitter. The Z3801A manual suggest using LMR 400 cable which is a 50 ohm cable which is compatible with the antenna. The thunderbolt which I receive has a type F connector and the thunderbolt manual suggest using 75 ohm rg59 cable. Will I have a problem connecting the thunderbolt to the smartsplitter using LRM400 50 ohm cable? The thunderbolt which I received came with a type f to bnc connector, but isn't a bnc connector underrated to handle the 1.5 GHz signal? Thanks, Jeff ___ 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] Z3801A ThunderBolt USING SAME ANTENNA?
Hi, I am trying to set up a Z3801A and a ThunderBolt to operate off of one symmetricom 58532A antenna using a symmetricom 4-port smartsplitter. The Z3801A manual suggest using LMR 400 cable which is a 50 ohm cable which is compatible with the antenna. The thunderbolt which I receive has a type F connector and the thunderbolt manual suggest using 75 ohm rg59 cable. Will I have a problem connecting the thunderbolt to the smartsplitter using LRM400 50 ohm cable? The thunderbolt which I received came with a type f to bnc connector, but isn't a bnc connector underrated to handle the 1.5 GHz signal? Thanks, Jeff ___ 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.
Re: [time-nuts] Z3801A ThunderBolt USING SAME ANTENNA?
If the cable is long enough, the discontinuities brought by using a BNC connector should not be too much of a problem, unless you are trying to extract the very last ounce of performance from the Thunderbolt. A long cable will have significant attenuation, and that will absorb most of the reflections caused by the impedance mismatch and bring them down to the noise level. This subject has been covered at length not very long ago (a few months?), so a look through the archives might bring back the thread. You might want to read the Thunderbolt manual to get Trimble's official position on the subject. Trimble has done a good job of confusing people by specifying their equipment for 50 ohm operation but recommending 75 ohm cable and using F connectors on the Thunderbolt and the Bullet antenna. I surmise that for the Thunderbolt's intended application (cell site synchronization), the difference was not worth worrying about. For the true Time-Nuts, that may not be good enough. Didier KO4BB -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of jshank Sent: Tuesday, July 08, 2008 8:45 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Z3801A ThunderBolt USING SAME ANTENNA? Hi, I am trying to set up a Z3801A and a ThunderBolt to operate off of one symmetricom 58532A antenna using a symmetricom 4-port smartsplitter. The Z3801A manual suggest using LMR 400 cable which is a 50 ohm cable which is compatible with the antenna. The thunderbolt which I receive has a type F connector and the thunderbolt manual suggest using 75 ohm rg59 cable. Will I have a problem connecting the thunderbolt to the smartsplitter using LRM400 50 ohm cable? The thunderbolt which I received came with a type f to bnc connector, but isn't a bnc connector underrated to handle the 1.5 GHz signal? Thanks, Jeff ___ 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 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.
Re: [time-nuts] Z3801A ThunderBolt USING SAME ANTENNA?
jshank wrote: Bruce, Do I need to spend the extra $ for LMR400 cable or could I just use rg58 for a total run of 60 feet. Jeff Jeff A conservative approach would be to use a cable that has an attenuation of no more than 10dB (the attenuation of the cable supplied in the Trimble Thunderbolt starter kit). For standard RG58 this can mean no more than about 30ft. This only applies if the antenna preamp gain is similar to that of the Trimble bullet antenna. _Minimum Antenna gain for Thunderbolt_ http://trl.trimble.com/docushare/dsweb/Get/Document-30908/Product Bullentin 200213.pdf http://trl.trimble.com/docushare/dsweb/Get/Document-30908/Product%20Bullentin%20200213.pdf Above link specifies a minimum of 20dB gain at Thunderbolt input. Thus with 23 dBattenuation (cable plus active splitter) you would need to use an antenna with at least 43dB gain preferably a little more. With 10dB of cable attenuation and 3dB maximum splitter loss the antenna preamp gain should be at least 33dB. The 5V Bullet III antenna has 35dB gain and thus allows a maximum attenuation (cable plus splitter) of about 15dB, preferably a little less, when used with a Thunderbolt. GPS Timing antennas with higher gains (50dB) are available. 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 instructions there.
