I need a distribution amp for my Tbolt , with 6..8+ outputs The TAPR-1 is NA , and the successor status is ???. I need it for distributing 10Mhz ref-clock to Counters (HP,Racal,Phillips), a Rigol Sig-gen & maybe Oscilloscopes etc. It's for "better than ocxo/hobby use" , and not Tnut (ps accuracy). I have seen suggestions for using a video distributiution unit. But in my part of the world (EU) , there isn't a lot on "eby". I have seen some RGB amps , and was wondering if i could use those ? Could i use a 1:6 RGB unit for : Tbolt on R , FEI-5680A on G - and ?? on B ? I'm not experienced (yet) in the analog domain. If i go (simple diy) Would this one work (also wo. the trafo's) ? http://www.oz9fw.dk/PDF%20files/rubidium.pdf I do have some trafo's on an old 10Mhz 8-chan Hub , that i might be able to salvage if needed. Thanx for any input/hints CFo - T-Nut beginner Denmark.

I think people have used video amps. I got one recently for nearly zero cost and it works as spec'd but video signals are typically 1 volt peak to peak and the amp is spec'd for "10MHz, 1dB" which means I'm right at the limit and I'm a 1 dB down, just as the spec says. Is 1V P-P enough for your equipment? This amp is easy to modify and I can greatly improve the specs by running it at +/- 15V rather then the +/-5V it now uses. So, my opinion: Video distribution amps can work but you'll be right on the edge of the spec'd limits all around. On Sun, Mar 25, 2012 at 9:26 AM, cfo <xnews3@luna.kyed.com> wrote: > I need a distribution amp for my Tbolt , with 6..8+ outputs > > The TAPR-1 is NA , and the successor status is ???. > > I need it for distributing 10Mhz ref-clock to Counters > (HP,Racal,Phillips), a Rigol Sig-gen & maybe Oscilloscopes etc. > > It's for "better than ocxo/hobby use" , and not Tnut (ps accuracy). > > I have seen suggestions for using a video distributiution unit. > But in my part of the world (EU) , there isn't a lot on "eby". > I have seen some RGB amps , and was wondering if i could use those ? > > Could i use a 1:6 RGB unit for : Tbolt on R , FEI-5680A on G  - and ?? on > B ? > > I'm not experienced (yet) in the analog domain. > > If i go (simple diy) Would this one work  (also wo. the trafo's) ? > http://www.oz9fw.dk/PDF%20files/rubidium.pdf > > I do have some trafo's on an old 10Mhz 8-chan Hub , that i might be able > to salvage if needed. > > Thanx for any input/hints > > CFo - T-Nut beginner Denmark. > > > > _______________________________________________ > 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. -- Chris Albertson Redondo Beach, California

Chris, that's got to be a really old video distribution amplifier. I was just given a thin rack-mount video distribution amplifier with ten outputs and the specification says 300 MHz bandwidth at 3 dB. I have not measured its output level. It is made by Kramer and has BNC and S-video in/out but no RCA composite video connectors. Well, that's the published spec; I have not tested it on my Tek 2712. We are not talking about critical phase relationships, just distributing 10 MHz for sig generators and counters. Larry On 3/25/2012 11:01 AM, Chris Albertson wrote: > I think people have used video amps. I got one recently for nearly > zero cost and it works as spec'd but video signals are typically 1 > volt peak to peak and the amp is spec'd for "10MHz, 1dB" which means > I'm right at the limit and I'm a 1 dB down, just as the spec says. > Is 1V P-P enough for your equipment? This amp is easy to modify > and I can greatly improve the specs by running it at +/- 15V rather > then the +/-5V it now uses. > > So, my opinion: Video distribution amps can work but you'll be right > on the edge of the spec'd limits all around. ... -- Best wishes, Larry McDavid W6FUB Anaheim, CA (20 miles southeast of Los Angeles, near Disneyland)

cfo wrote: > I need a distribution amp for my Tbolt , with 6..8+ outputs > > The TAPR-1 is NA , and the successor status is ???. > > I need it for distributing 10Mhz ref-clock to Counters > (HP,Racal,Phillips), a Rigol Sig-gen& maybe Oscilloscopes etc. > > It's for "better than ocxo/hobby use" , and not Tnut (ps accuracy). > > I have seen suggestions for using a video distributiution unit. > But in my part of the world (EU) , there isn't a lot on "eby". > I have seen some RGB amps , and was wondering if i could use those ? > > Could i use a 1:6 RGB unit for : Tbolt on R , FEI-5680A on G - and ?? on > B ? > > I'm not experienced (yet) in the analog domain. > > If i go (simple diy) Would this one work (also wo. the trafo's) ? > http://www.oz9fw.dk/PDF%20files/rubidium.pdf > > I do have some trafo's on an old 10Mhz 8-chan Hub , that i might be able > to salvage if needed. > > Thanx for any input/hints > > CFo - T-Nut beginner Denmark. > > > > _______________________________________________ > 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. > > Winding your own transformers isnt particularly difficult if you have suitable (binocular) cores. The discrete amplifier shown has a class AB output stage, lower distortion is possible if a class A output stage is used (requires an extra resistor between the output stage emitters and an additional diode in series with the LED). With a Class A output stage the 39 ohm resistors should be replaced by a a pair of 100 ohm resistors to match the load. Significantly lower distortion is possible if feedback from the output to the input stage is used. If the feedback gain is unity (or less) at dc higher AC gains won't significantly degrade the close in phase noise. A different amplifier topology using the same number of transistors will allow a higher reverse isolation to be achieved. One problem with video distribution units (aside from the relatively high phase noise floor) is the limited output drive available. For some purposes 16-20dBm outputs are desirable. Bruce

Well the easy answer. The older 1984 video amps would roll off above 6 MC or so. However as the IC technology took over they easily could do 30 Mhz. I have used Grass valley 8500 series for at least 10-15 years and the work very well. I also have sets of Leitch DAs that are fine. Picked up the whole tray for some silly amount of $ 20 I think. I prefer the simple 8601 DAs but have 8604 delay days and they can all be made into simple DAs with a few jumpers that are on the boards. I have also used a rgb da 6 output for each channel. No issue at all. One comment you would want to insure the amps are ac coupled and clamping turned off since there is no sync signal to establish the clamp level. Regards Paul WB8TSL On Sun, Mar 25, 2012 at 2:14 PM, Bruce Griffiths <bruce.griffiths@xtra.co.nz > wrote: > cfo wrote: > >> I need a distribution amp for my Tbolt , with 6..8+ outputs >> >> The TAPR-1 is NA , and the successor status is ???. >> >> I need it for distributing 10Mhz ref-clock to Counters >> (HP,Racal,Phillips), a Rigol Sig-gen& maybe Oscilloscopes etc. >> >> >> It's for "better than ocxo/hobby use" , and not Tnut (ps accuracy). >> >> I have seen suggestions for using a video distributiution unit. >> But in my part of the world (EU) , there isn't a lot on "eby". >> I have seen some RGB amps , and was wondering if i could use those ? >> >> Could i use a 1:6 RGB unit for : Tbolt on R , FEI-5680A on G - and ?? on >> B ? >> >> I'm not experienced (yet) in the analog domain. >> >> If i go (simple diy) Would this one work (also wo. the trafo's) ? >> http://www.oz9fw.dk/PDF%**20files/rubidium.pdf<http://www.oz9fw.dk/PDF%20files/rubidium.pdf> >> >> I do have some trafo's on an old 10Mhz 8-chan Hub , that i might be able >> to salvage if needed. >> >> Thanx for any input/hints >> >> CFo - T-Nut beginner Denmark. >> >> >> >> ______________________________**_________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/** >> mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> >> and follow the instructions there. >> >> >> > Winding your own transformers isnt particularly difficult if you have > suitable (binocular) cores. > The discrete amplifier shown has a class AB output stage, lower distortion > is possible if a class A output stage is used (requires an extra resistor > between the output stage emitters and an additional diode in series with > the LED). > With a Class A output stage the 39 ohm resistors should be replaced by a a > pair of 100 ohm resistors to match the load. > Significantly lower distortion is possible if feedback from the output to > the input stage is used. > If the feedback gain is unity (or less) at dc higher AC gains won't > significantly degrade the close in phase noise. > A different amplifier topology using the same number of transistors will > allow a higher reverse isolation to be achieved. > > One problem with video distribution units (aside from the relatively high > phase noise floor) is the limited output drive available. For some purposes > 16-20dBm outputs are desirable. > > Bruce > > > ______________________________**_________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/** > mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > and follow the instructions there. >

Bruce Griffiths wrote: > cfo wrote: >> I need a distribution amp for my Tbolt , with 6..8+ outputs >> >> The TAPR-1 is NA , and the successor status is ???. >> >> I need it for distributing 10Mhz ref-clock to Counters >> (HP,Racal,Phillips), a Rigol Sig-gen& maybe Oscilloscopes etc. >> >> It's for "better than ocxo/hobby use" , and not Tnut (ps accuracy). >> >> I have seen suggestions for using a video distributiution unit. >> But in my part of the world (EU) , there isn't a lot on "eby". >> I have seen some RGB amps , and was wondering if i could use those ? >> >> Could i use a 1:6 RGB unit for : Tbolt on R , FEI-5680A on G - and >> ?? on >> B ? >> >> I'm not experienced (yet) in the analog domain. >> >> If i go (simple diy) Would this one work (also wo. the trafo's) ? >> http://www.oz9fw.dk/PDF%20files/rubidium.pdf >> >> I do have some trafo's on an old 10Mhz 8-chan Hub , that i might be able >> to salvage if needed. >> >> Thanx for any input/hints >> >> CFo - T-Nut beginner Denmark. >> >> >> >> _______________________________________________ >> 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. >> > Winding your own transformers isnt particularly difficult if you have > suitable (binocular) cores. > The discrete amplifier shown has a class AB output stage, lower > distortion is possible if a class A output stage is used (requires an > extra resistor between the output stage emitters and an additional > diode in series with the LED). > With a Class A output stage the 39 ohm resistors should be replaced by > a a pair of 100 ohm resistors to match the load. > Significantly lower distortion is possible if feedback from the output > to the input stage is used. > If the feedback gain is unity (or less) at dc higher AC gains won't > significantly degrade the close in phase noise. > A different amplifier topology using the same number of transistors > will allow a higher reverse isolation to be achieved. > > One problem with video distribution units (aside from the relatively > high phase noise floor) is the limited output drive available. For > some purposes 16-20dBm outputs are desirable. > > Bruce A circuit schematic for a current feedback triple with reasonably low noise and distortion is attached. Bruce

Sounds like Paul and I have similar DA's or will soon when a Leitch gets to the front porch next week. Its bandwidth is spec'd at 30 MHz. The only question I have on using DA's is the effect of them being designed to work in a 75 ohm environment. One thing to watch out for is what cards they have in them. -pete On Sun, Mar 25, 2012 at 11:39 AM, paul swed <paulswedb@gmail.com> wrote: > Well the easy answer. > The older 1984 video amps would roll off above 6 MC or so. > However as the IC technology took over they easily could do 30 Mhz. > I have used Grass valley 8500 series for at least 10-15 years and the work > very well. > I also have sets of Leitch DAs that are fine. > Picked up the whole tray for some silly amount of $ 20 I think. > I prefer the simple 8601 DAs but have 8604 delay days and they can all be > made into simple DAs with a few jumpers that are on the boards. > I have also used a rgb da 6 output for each channel. No issue at all. > One comment you would want to insure the amps are ac coupled and clamping > turned off since there is no sync signal to establish the clamp level. > Regards > Paul > WB8TSL > > On Sun, Mar 25, 2012 at 2:14 PM, Bruce Griffiths <bruce.griffiths@xtra.co.nz >> wrote: > >> cfo wrote: >> >>> I need a distribution amp for my Tbolt , with 6..8+ outputs >>> >>> The TAPR-1 is NA , and the successor status is ???. >>> >>> I need it for distributing 10Mhz ref-clock to Counters >>> (HP,Racal,Phillips), a Rigol Sig-gen&  maybe Oscilloscopes etc. >>> >>> >>> It's for "better than ocxo/hobby use" , and not Tnut (ps accuracy). >>> >>> I have seen suggestions for using a video distributiution unit. >>> But in my part of the world (EU) , there isn't a lot on "eby". >>> I have seen some RGB amps , and was wondering if i could use those ? >>> >>> Could i use a 1:6 RGB unit for : Tbolt on R , FEI-5680A on G  - and ?? on >>> B ? >>> >>> I'm not experienced (yet) in the analog domain. >>> >>> If i go (simple diy) Would this one work  (also wo. the trafo's) ? >>> http://www.oz9fw.dk/PDF%**20files/rubidium.pdf<http://www.oz9fw.dk/PDF%20files/rubidium.pdf> >>> >>> I do have some trafo's on an old 10Mhz 8-chan Hub , that i might be able >>> to salvage if needed. >>> >>> Thanx for any input/hints >>> >>> CFo - T-Nut beginner Denmark. >>> >>> >>> >>> ______________________________**_________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/** >>> mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> >>> and follow the instructions there. >>> >>> >>> >> Winding your own transformers isnt particularly difficult if you have >> suitable (binocular) cores. >> The discrete amplifier shown has a class AB output stage, lower distortion >> is possible if a class A output stage is used (requires an extra resistor >> between the output stage emitters and an additional diode in series with >> the LED). >> With a Class A output stage the 39 ohm resistors should be replaced by a a >> pair of 100 ohm resistors to match the load. >> Significantly lower distortion is possible if feedback from the output to >> the input stage is used. >> If the feedback gain is unity (or less) at dc higher AC gains won't >> significantly degrade the close in phase noise. >> A different amplifier topology using the same number of transistors will >> allow a higher reverse isolation to be achieved. >> >> One problem with video distribution units (aside from the relatively high >> phase noise floor) is the limited output drive available. For some purposes >> 16-20dBm outputs are desirable. >> >> Bruce >> >> >> ______________________________**_________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/** >> mailman/listinfo/time-nuts<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.

Bruce wrote: >A circuit schematic for a current feedback triple with reasonably >low noise and distortion is attached. One caution regarding the 100 uH inductor (L3) -- many inductors of this value exhibit self-resonance below 10 MHz, so some care may be necessary in selection. Best regards, Charles

Has anyone measured Phase Noise on any of these distribution amps? By looking at how widely the PN specs vary on the application specific Symmetricom and HP DA's it would be interesting to see how well these video da's perform in comparison. Thomas Knox > Date: Sun, 25 Mar 2012 12:28:56 -0700 > From: pete@petelancashire.com > To: time-nuts@febo.com > Subject: Re: [time-nuts] Distribution amp - Use a video amp unit ? > > Sounds like Paul and I have similar DA's or will soon when a Leitch gets to the > front porch next week. Its bandwidth is spec'd at 30 MHz. > > The only question I have on using DA's is the effect of them being designed to > work in a 75 ohm environment. > > One thing to watch out for is what cards they have in them. > > -pete > > > > On Sun, Mar 25, 2012 at 11:39 AM, paul swed <paulswedb@gmail.com> wrote: > > Well the easy answer. > > The older 1984 video amps would roll off above 6 MC or so. > > However as the IC technology took over they easily could do 30 Mhz. > > I have used Grass valley 8500 series for at least 10-15 years and the work > > very well. > > I also have sets of Leitch DAs that are fine. > > Picked up the whole tray for some silly amount of $ 20 I think. > > I prefer the simple 8601 DAs but have 8604 delay days and they can all be > > made into simple DAs with a few jumpers that are on the boards. > > I have also used a rgb da 6 output for each channel. No issue at all. > > One comment you would want to insure the amps are ac coupled and clamping > > turned off since there is no sync signal to establish the clamp level. > > Regards > > Paul > > WB8TSL > > > > On Sun, Mar 25, 2012 at 2:14 PM, Bruce Griffiths <bruce.griffiths@xtra.co.nz > >> wrote: > > > >> cfo wrote: > >> > >>> I need a distribution amp for my Tbolt , with 6..8+ outputs > >>> > >>> The TAPR-1 is NA , and the successor status is ???. > >>> > >>> I need it for distributing 10Mhz ref-clock to Counters > >>> (HP,Racal,Phillips), a Rigol Sig-gen& maybe Oscilloscopes etc. > >>> > >>> > >>> It's for "better than ocxo/hobby use" , and not Tnut (ps accuracy). > >>> > >>> I have seen suggestions for using a video distributiution unit. > >>> But in my part of the world (EU) , there isn't a lot on "eby". > >>> I have seen some RGB amps , and was wondering if i could use those ? > >>> > >>> Could i use a 1:6 RGB unit for : Tbolt on R , FEI-5680A on G - and ?? on > >>> B ? > >>> > >>> I'm not experienced (yet) in the analog domain. > >>> > >>> If i go (simple diy) Would this one work (also wo. the trafo's) ? > >>> http://www.oz9fw.dk/PDF%**20files/rubidium.pdf<http://www.oz9fw.dk/PDF%20files/rubidium.pdf> > >>> > >>> I do have some trafo's on an old 10Mhz 8-chan Hub , that i might be able > >>> to salvage if needed. > >>> > >>> Thanx for any input/hints > >>> > >>> CFo - T-Nut beginner Denmark. > >>> > >>> > >>> > >>> ______________________________**_________________ > >>> time-nuts mailing list -- time-nuts@febo.com > >>> To unsubscribe, go to https://www.febo.com/cgi-bin/** > >>> mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > >>> and follow the instructions there. > >>> > >>> > >>> > >> Winding your own transformers isnt particularly difficult if you have > >> suitable (binocular) cores. > >> The discrete amplifier shown has a class AB output stage, lower distortion > >> is possible if a class A output stage is used (requires an extra resistor > >> between the output stage emitters and an additional diode in series with > >> the LED). > >> With a Class A output stage the 39 ohm resistors should be replaced by a a > >> pair of 100 ohm resistors to match the load. > >> Significantly lower distortion is possible if feedback from the output to > >> the input stage is used. > >> If the feedback gain is unity (or less) at dc higher AC gains won't > >> significantly degrade the close in phase noise. > >> A different amplifier topology using the same number of transistors will > >> allow a higher reverse isolation to be achieved. > >> > >> One problem with video distribution units (aside from the relatively high > >> phase noise floor) is the limited output drive available. For some purposes > >> 16-20dBm outputs are desirable. > >> > >> Bruce > >> > >> > >> ______________________________**_________________ > >> time-nuts mailing list -- time-nuts@febo.com > >> To unsubscribe, go to https://www.febo.com/cgi-bin/** > >> mailman/listinfo/time-nuts<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. > > _______________________________________________ > 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.

On Sun, Mar 25, 2012 at 12:28 PM, Pete Lancashire <pete@petelancashire.com> wrote: > > The only question I have on using DA's is the effect of them being designed to > work in a 75 ohm environment. Swap out a few resistors and you can fix the above problem. unless they used those 75 ohm BNCs but those are rare and if you are a true "nut" you can replace them. In my amp the resistors are all very easy to swap through hole 1/4W types Chris Albertson Redondo Beach, California