This is the latest purchase: https://www.amazon.com/gp/product/B0CW3B9ZM8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
On Tue, Aug 27, 2024 at 3:43 PM Carl Peterson <cpeter...@portnetworks.com> wrote: > Hey Josh, > > What cheap Chinese OTDRs are you using? I'm in the market. > > On Tue, Aug 27, 2024 at 2:31 PM Josh Luthman <j...@imaginenetworksllc.com> > wrote: > >> So far every time we've used the OTDR it's been accurate within 1 foot. >> >> On Tue, Aug 27, 2024 at 12:55 PM Trey Scarborough <t...@3dsc.co> wrote: >> >>> The only thing you have to worry about with shorter cables is the >>> reflection. In some instances with dirty connector at just the right >>> connector you can get reflection back in to the transmitter that can cause >>> errors, the tx to shut down or premature failure. This is very uncommon >>> with LR 10G and less optics and can be prevented from making sure you have >>> clean connectors. Check the RX and TX levels and make sure you don't have >>> excessive loss. With 100G its a little different story due to the combined >>> power of multiple channels, but still can be prevented by cleaning >>> connectors, but in some instances Ive had to use attenuation when mixing >>> different vendor optics. >>> >>> The using no launch on an OTDR most automatically calibrating OTDRs will >>> work without one. Your results can be off though. Most of the lower cost >>> ones are also lower powered and have less of an RX sensitivity so they >>> don't suffer as much from the reflections interfering when testing. I can >>> test all day long with my little otdrs without one, but my long range 200k+ >>> units I have to have a minimum of a 1k spool on it or you see ghosts. They >>> will show up as repeating events at even intervals. Not something you will >>> see on shorter runs either. >>> >>> >>> On 8/26/24 4:31 PM, Ken Hohhof wrote: >>> >>> I should note that apparently I used to do this with direct attach >>> cables (DAC) but I think that was a pain, one more thing to stock and to >>> bring with for projects. Whereas I’d always have boxes full of SFPs and >>> fiber patch cords. >>> >>> >>> >>> *From:* AF <af-boun...@af.afmug.com> <af-boun...@af.afmug.com> *On >>> Behalf Of *Josh Luthman >>> *Sent:* Monday, August 26, 2024 4:20 PM >>> *To:* AnimalFarm Microwave Users Group <af@af.afmug.com> >>> <af@af.afmug.com> >>> *Subject:* Re: [AFMUG] fiber patch cables >>> >>> >>> >>> People say you need a launch cable but our cheap china OTDRs have no >>> issues seeing the connector at the end of the patch cable and stuff >>> beyond. I bought a big launch cable back in the day and never use it >>> anymore. >>> >>> >>> >>> Might be different with AE? >>> >>> >>> >>> On Mon, Aug 26, 2024 at 5:16 PM <ch...@go-mtc.com> wrote: >>> >>> Only minimum length I know of is the OTDR dead zone. If that is a >>> problem you purposely lengthen the cable with a launch cable. >>> >>> >>> >>> *From:* Josh Luthman >>> >>> *Sent:* Monday, August 26, 2024 1:59 PM >>> >>> *To:* AnimalFarm Microwave Users Group >>> >>> *Subject:* Re: [AFMUG] fiber patch cables >>> >>> >>> >>> Reddit is wrong. Gasp. >>> >>> >>> >>> Connectors are loss, there is more loss in either one of the connectors >>> than there is the single mode glass. >>> >>> >>> >>> Between a switch/router in a rack what I see all the time is long (like >>> 5/10/15 feet) cables and then put the slack in a loop along the posts. >>> >>> >>> >>> On Mon, Aug 26, 2024 at 1:19 PM TJ Trout <t...@voltbb.com> wrote: >>> >>> Patchbox makes some great products, their fiber system is pretty slick >>> but expensive. >>> >>> >>> >>> Cable length is irrelevant it's optical budget / Rx signal strength. >>> Normally on 2-20k LR optics you are ok with any length cable, 40km+ needs a >>> pad on short spans. (Attenuator) >>> >>> >>> >>> On Mon, Aug 26, 2024, 8:29 AM Ken Hohhof <khoh...@kwom.com> wrote: >>> >>> Is there a minimum length for a single mode fiber patch cable? >>> >>> >>> >>> I have been using 1 meter cables and they are almost always too long, >>> I’m talking about going between routers and switches in a rack, stuff like >>> that. I see that FS sells 0.5 meter cables, but I saw somewhere like maybe >>> on Reddit someone claiming there was a minimum length. Given SM fiber and >>> LR optics, I don’t see how 0.5 or 1.0 meter would be different they are >>> both essentially zero length. >>> >>> >>> >>> Probably there’s some kind of cable tray or cable management solution I >>> could be using but I’ve never liked such things. >>> >>> -- >>> AF mailing list >>> AF@af.afmug.com >>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>> >>> -- >>> AF mailing list >>> AF@af.afmug.com >>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>> >>> ------------------------------ >>> >>> -- >>> AF mailing list >>> AF@af.afmug.com >>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>> >>> -- >>> AF mailing list >>> AF@af.afmug.com >>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>> >>> >>> -- >>> AF mailing list >>> AF@af.afmug.com >>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>> >> -- >> AF mailing list >> AF@af.afmug.com >> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >> > > > -- > > Carl Peterson > > *PORT NETWORKS* > > 401 E Pratt St, Ste 2553 > > Baltimore, MD 21202 > > (410) 637-3707 > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com >
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