Re: [time-nuts] distribution amps for 200 MHz
On 9/16/2020 5:59 PM, ed breya wrote: Depending on the performance level, I'd tend to go with the crowd recommending CATV distribution type stuff. If the trip is short, then maybe you don't have to worry about 75 vs 50 ohms too much. If the trip The RF2312 I mentioned IS a CATV type amplifier. However, the NIST paper I cited says it has very low phase noise. Rick ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] distribution amps for 200 MHz
The answer lies somewhere between lots and lots of small amplifiers and associated parts, and one big one driving a tree of passive splitters. Are all the widgets the same? How much isolation is needed? How "good" does it have to be? How far away is everything? Are there ground loop/EMC issues? Depending on the performance level, I'd tend to go with the crowd recommending CATV distribution type stuff. If the trip is short, then maybe you don't have to worry about 75 vs 50 ohms too much. If the trip is long, and 50 ohm cable is to be used, I'd recommend a 75 ohm CATV line driver power amp, with matching transformers at the in and out, then a tree of 50 ohm splitters. The kind of amplifier I'm picturing would be a modern, non-obsolete type. I don't know of any offhand, but would think the function is still needed. I'm familiar with the big old hybrid ones that are probably all obsolete, like the MHW5342A. If you go with one big amp. then the matching only needs to be at one place, and the rest of the stuff can be whatever is needed. Depending on budget, it should be possible to find a 50 ohm COTS (or even custom made) VHF power amp module, and skip the DIY part. If you need extremely high performance provided by using lots of special or individual amps, then you gotta do what you gotta do - but that's a helluva lot of parts. If there are ground loop/EMC issues, It may be desirable to use transformer coupled and isolated outputs if needed, even if impedance matching is already OK. That would be a lot of parts too. Ed ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] distribution amps for 200 MHz
Jim, Look at a TI THS4509 with a minicircuit balun, driving passive CATV splitters. -Jay On Tuesday, September 15, 2020, 12:23:21 PM PDT, jimlux wrote: For work, I'm looking to distribute 200 MHz to 44 widgets.. The usual SRS, etc. boxes max out at 100 MHz. Any ideas? (The going in position is "buy a bunch of minicircuits amps and dividers and assemble it") Tnx Jim ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] Distribution amps for 200 MHz
We have a Timetech 5/10 MHz distribution unit at my work whohad one output burned. Inside, the circuit board was full of IC'smarked "A83A" which I tried to decode. I got one hit on "Google"which was Texas Instruments LMH6702MF This is a broad bandOP-Amp in a SOT23-5 package. Maybe it will suit your needs. Cheers Ulf KylenfallSM6GXV ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] distribution amps for 200 MHz
Some CATV distribution amplifiers have built-in 4 or 8 way splitters and work over 60-900 MHz. They are cheap enough that's it's worth trying. Didier KO4BB On Tue, Sep 15, 2020, 4:57 PM Poul-Henning Kamp wrote: > > jimlux writes: > > > For work, I'm looking to distribute 200 MHz to 44 widgets.. > > The usual SRS, etc. boxes max out at 100 MHz. Any ideas? > > A lot of video-production amps would have no trouble with that > but they're all 75 Ohm... > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] distribution amps for 200 MHz
jimlux writes: > For work, I'm looking to distribute 200 MHz to 44 widgets.. > The usual SRS, etc. boxes max out at 100 MHz. Any ideas? A lot of video-production amps would have no trouble with that but they're all 75 Ohm... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] distribution amps for 200 MHz
I also need ~200 MHz buffers for a client. See: State-of-the-Art RF Signal Generation From Optical Frequency Division Sept 2013 IEEE Trans UFFC, p 1796 In Table I (top of page 1798) they list the RFMD RF2312 amplifier. Table II top of page 1799 shows that this is good for -150 dBc/Hz at 1 Hz for a 5 MHz carrier. The bandwidth of this amplifier goes way beyond 200 MHz, so I am assuming the phase noise should be good at 200 MHz. Maybe not 150 dBc/Hz, but still respectable for 200 MHz, vs other amps. RFMD went through a half dozen mergers and the RF2313 is now made by Qorvo and sold thru the usual distributors. I characterized it and it wants to be used in a 75 ohm, not 50 ohm system. There are always transfomers... My HP11848 went south so I was never able to measure its phase noise at 200 MHz. Anyone have have an 11848 to sell? If someone would like to measure it for me, I will be happy to send an evaluation board. Rick N6RK On 9/15/2020 11:17 AM, jimlux wrote: For work, I'm looking to distribute 200 MHz to 44 widgets.. The usual SRS, etc. boxes max out at 100 MHz. Any ideas? (The going in position is "buy a bunch of minicircuits amps and dividers and assemble it") Tnx Jim ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] distribution amps for 200 MHz
Cheap Chinese rf amps ebay, also TV splitters On 2020-09-15 12:17, jimlux wrote: For work, I'm looking to distribute 200 MHz to 44 widgets.. The usual SRS, etc. boxes max out at 100 MHz. Any ideas (The going in position is "buy a bunch of minicircuits amps and dividers and assemble it") Tnx Jim ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. -- Dr. Don Latham AJ7LL PO Box 404, Frenchtown, MT, 59834 VOX: 406-626-4304 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] distribution amps for 200 MHz
Jim You beat me to the exact answer I would have given you. Its a bit trickier than that in the splitter setup. But I know from previous posts you know that already. Thinking noise from the amps may be the trickiest part. Regards Paul WB8TSL On Tue, Sep 15, 2020 at 3:23 PM jimlux wrote: > For work, I'm looking to distribute 200 MHz to 44 widgets.. > The usual SRS, etc. boxes max out at 100 MHz. Any ideas? > > (The going in position is "buy a bunch of minicircuits amps and dividers > and assemble it") > > Tnx > Jim > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] distribution amps for 200 MHz
For work, I'm looking to distribute 200 MHz to 44 widgets.. The usual SRS, etc. boxes max out at 100 MHz. Any ideas? (The going in position is "buy a bunch of minicircuits amps and dividers and assemble it") Tnx Jim ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
