Topics

10MHz buffer amplifier

Ed G3VPF
 

I am in the process of replacing multiple 10 MHz reference sources with a single high-quality OCXO unit which will require four outputs. Can anyone recommend a suitable buffer amplifier in stripline or DIL package that would be suitable for driving ~10dBm into 50 Ohms? The gain should be 10-15 dB.

Ed G3VPF IO80RQ

Paul Randall G3NJV
 

Ed, have a look at video amplifier chips. I’m building a box to do the same job based on a cheap Extron DA2 video dist amp which uses OPA3691 which are triple op-amps.

 

Sent from Mail for Windows 10

 


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Ed G3VPF <g3vpf@...>
Sent: Thursday, January 2, 2020 8:43:41 PM
To: ukmicrowaves@groups.io <ukmicrowaves@groups.io>
Subject: [UKMicrowaves] 10MHz buffer amplifier
 
I am in the process of replacing multiple 10 MHz reference sources with a single high-quality OCXO unit which will require four outputs. Can anyone recommend a suitable buffer amplifier in stripline or DIL package that would be suitable for driving ~10dBm into 50 Ohms? The gain should be 10-15 dB.

Ed G3VPF IO80RQ

Andy G4JNT
 

I used the LM7171 opamp.    It can drive 50R, so two 50R resistors from the O/P going to two outputs give two backwards-matched ports.   Isolation between those is ~ 20dB    One op-amp buffer per pair of outputs then isolation between ports on separate opamps >80dB

OPA inputs are Hi-Z, so several can be paralleled  from drive from the master source.



On Thu, 2 Jan 2020 at 20:43, Ed G3VPF <g3vpf@...> wrote:
I am in the process of replacing multiple 10 MHz reference sources with a single high-quality OCXO unit which will require four outputs. Can anyone recommend a suitable buffer amplifier in stripline or DIL package that would be suitable for driving ~10dBm into 50 Ohms? The gain should be 10-15 dB.

Ed G3VPF IO80RQ

Andy G4JNT
 

Knew it was published somewhere

Ignore the 5Mhz doubler section.
 


On Thu, 2 Jan 2020 at 21:00, Andy G4JNT via Groups.Io <andy.g4jnt=gmail.com@groups.io> wrote:
I used the LM7171 opamp.    It can drive 50R, so two 50R resistors from the O/P going to two outputs give two backwards-matched ports.   Isolation between those is ~ 20dB    One op-amp buffer per pair of outputs then isolation between ports on separate opamps >80dB

OPA inputs are Hi-Z, so several can be paralleled  from drive from the master source.



On Thu, 2 Jan 2020 at 20:43, Ed G3VPF <g3vpf@...> wrote:
I am in the process of replacing multiple 10 MHz reference sources with a single high-quality OCXO unit which will require four outputs. Can anyone recommend a suitable buffer amplifier in stripline or DIL package that would be suitable for driving ~10dBm into 50 Ohms? The gain should be 10-15 dB.

Ed G3VPF IO80RQ

Paul Randall G3NJV
 

Ed, sorry, previous post sent without finishing. If you are building a free standing unit, have a look for an Extron DA2 or DA4 RGBHV distribution amplifier, I got mine on ebay for £22 delivered. You get a decent box, power supply, in/out sockets and pre-built amp pcb. Saves a huge amount of work. Box is mostly empty so plenty of room for GPSDO, TCXO, dividers etc.

HNY Paul G3NJV

 

Sent from Mail for Windows 10

 


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Ed G3VPF <g3vpf@...>
Sent: Thursday, January 2, 2020 8:43:41 PM
To: ukmicrowaves@groups.io <ukmicrowaves@groups.io>
Subject: [UKMicrowaves] 10MHz buffer amplifier
 
I am in the process of replacing multiple 10 MHz reference sources with a single high-quality OCXO unit which will require four outputs. Can anyone recommend a suitable buffer amplifier in stripline or DIL package that would be suitable for driving ~10dBm into 50 Ohms? The gain should be 10-15 dB.

Ed G3VPF IO80RQ

DD1US
 

This one has transformers at the output to avoid ground bouncing / hum …

 

https://www.dd1us.de/Downloads/10%20MHz%20distribution%20unit%20with%204%20isolated%20outputs%20v3.pdf

 

Regards

 

Matthias

 

 

 

Von: UKMicrowaves@groups.io <UKMicrowaves@groups.io> Im Auftrag von Andy G4JNT
Gesendet: Donnerstag, 2. Januar 2020 22:09
An: UK Microwaves groups.io <UKMicrowaves@groups.io>
Betreff: Re: [UKMicrowaves] 10MHz buffer amplifier

 

Knew it was published somewhere

 

Ignore the 5Mhz doubler section.

 

Andy

 

 

 

On Thu, 2 Jan 2020 at 21:00, Andy G4JNT via Groups.Io <andy.g4jnt=gmail.com@groups.io> wrote:

I used the LM7171 opamp.    It can drive 50R, so two 50R resistors from the O/P going to two outputs give two backwards-matched ports.   Isolation between those is ~ 20dB    One op-amp buffer per pair of outputs then isolation between ports on separate opamps >80dB

 

OPA inputs are Hi-Z, so several can be paralleled  from drive from the master source.

 

Andy

 

 

 

On Thu, 2 Jan 2020 at 20:43, Ed G3VPF <g3vpf@...> wrote:

I am in the process of replacing multiple 10 MHz reference sources with a single high-quality OCXO unit which will require four outputs. Can anyone recommend a suitable buffer amplifier in stripline or DIL package that would be suitable for driving ~10dBm into 50 Ohms? The gain should be 10-15 dB.

 

Ed G3VPF IO80RQ

KENT BRITAIN
 

HUP had a kit for a 4 way 10 MHz divider.

Any of his kits still floating around?

Kent G8EMY

On Thursday, January 2, 2020, 3:09:41 PM CST, Andy G4JNT <andy.g4jnt@...> wrote:


Knew it was published somewhere

Ignore the 5Mhz doubler section.
 


On Thu, 2 Jan 2020 at 21:00, Andy G4JNT via Groups.Io <andy.g4jnt=gmail.com@groups.io> wrote:
I used the LM7171 opamp.    It can drive 50R, so two 50R resistors from the O/P going to two outputs give two backwards-matched ports.   Isolation between those is ~ 20dB    One op-amp buffer per pair of outputs then isolation between ports on separate opamps >80dB

OPA inputs are Hi-Z, so several can be paralleled  from drive from the master source.



On Thu, 2 Jan 2020 at 20:43, Ed G3VPF <g3vpf@...> wrote:
I am in the process of replacing multiple 10 MHz reference sources with a single high-quality OCXO unit which will require four outputs. Can anyone recommend a suitable buffer amplifier in stripline or DIL package that would be suitable for driving ~10dBm into 50 Ohms? The gain should be 10-15 dB.

Ed G3VPF IO80RQ

Daniel
 

Hi Ed,

try DF9NP here:
http://www.df9np.de/page4.html

Messplatz 10MHz FanOut Buffer with 10 Outputs/>
Supply +12V (also AVAILABLE for 5 to 8V )
Current all Outputs loaded with 100R 125mA
Input 0,6Vpp to 3Vpp
All Outputs with Filter, Pure Sinus
Default with 56R in series load 3Vpp , also possible with 100R in series at 2,2Vpp
LxW 95x53mm

I have been using this board in my shack/lab for more than 5 years. Works perfect.
Price is around 30 EUR. Hurry up, Brexit is coming!
All prices and circuit diagrams can be found here:

http://www.df9np.de/page5.html

No relation with the seller, just a happy customer.

73s
Daniel
DL3IAE

Neil Smith G4DBN
 

I have one of the 8-port kits still unbuilt, but I want to keep it to build on a special day. 

I already have one 4 port and one 8-port in use.  The 8-port was his first production upgrade board to turn a 4 into an 8.  They are by no means perfect, there is some port interaction and no transformer isolation.  When I boot my HP 8562A, it sends an output on the 10MHz port for a short time, which really messes up some of the other kit else connected to the same HUP box.

At this exact time I'm building a HUPrf e-field receive preamp and bias-tee kit.  I have seven more of those to build for a club project.

Sadly missed....

Neil G4DBN


On 02/01/2020 21:45, KENT BRITAIN wrote:
HUP had a kit for a 4 way 10 MHz divider.

Any of his kits still floating around?

Kent G8EMY

Dennis Anderson
 

I believe that SDR-Kits are selling some

Dennis G6YBC 




On Thursday, January 2, 2020, 10:14 pm, Neil Smith G4DBN <neil@...> wrote:

I have one of the 8-port kits still unbuilt, but I want to keep it to build on a special day. 

I already have one 4 port and one 8-port in use.  The 8-port was his first production upgrade board to turn a 4 into an 8.  They are by no means perfect, there is some port interaction and no transformer isolation.  When I boot my HP 8562A, it sends an output on the 10MHz port for a short time, which really messes up some of the other kit else connected to the same HUP box.

At this exact time I'm building a HUPrf e-field receive preamp and bias-tee kit.  I have seven more of those to build for a club project.

Sadly missed....

Neil G4DBN


On 02/01/2020 21:45, KENT BRITAIN wrote:
HUP had a kit for a 4 way 10 MHz divider.

Any of his kits still floating around?

Kent G8EMY

Rien Eradus PA0JME
 

I myself use the LT1253, neat dual video amp 8 pin package, cheap with ali-expres, easy gain setting using 2 external resistors

73es Rien PA0JME

Ed G3VPF
 

Many thanks for all the useful replies regarding the 10 MHz line driver. Perhaps a little more detail on my application is appropriate. I now have four portable systems for 23, 13, 6 and 3cms. As I have built each one I have built it as a standalone system with its own frequency reference so I now have an assortment of OCXO's of dubious origin and GPSDO's. I am now trying to integrate the four systems by using multi-band dish feeds and by reducing the number of support boxes. All four systems need a 10 MHz reference so I have invested in a high quality OCXO and now wish to feed it to all four systems. I am very space-limited and would like to put the system in the physical location of one of the GPSDO's. It means I have to build the unit into an identical box so the use of pre-built units is not appropriate.

The LM7171 has been suggested, but I tried this device driving 25MHz up a long piece of coax to the QO-100 LNB and found it was severely slew-rate limited. Changed to a BUF634 and this was OK. In this application the frequency is lower and the length of coax much less so the LM7171 may be OK. The BUF634 only has a gain of 0dB and in this case I need a gain of around 12dB so hence my quest for a suitable device.

I will follow-up some of the suggestions which may well be fruitful. Thanks once again for the assistance.

Ed, G3VPF IO80RQ


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Dennis Anderson via Groups.Io <g6ybc@...>
Sent: 03 January 2020 13:55
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] 10MHz buffer amplifier
 
I believe that SDR-Kits are selling some

Dennis G6YBC 




On Thursday, January 2, 2020, 10:14 pm, Neil Smith G4DBN <neil@...> wrote:

I have one of the 8-port kits still unbuilt, but I want to keep it to build on a special day. 

I already have one 4 port and one 8-port in use.  The 8-port was his first production upgrade board to turn a 4 into an 8.  They are by no means perfect, there is some port interaction and no transformer isolation.  When I boot my HP 8562A, it sends an output on the 10MHz port for a short time, which really messes up some of the other kit else connected to the same HUP box.

At this exact time I'm building a HUPrf e-field receive preamp and bias-tee kit.  I have seven more of those to build for a club project.

Sadly missed....

Neil G4DBN


On 02/01/2020 21:45, KENT BRITAIN wrote:
HUP had a kit for a 4 way 10 MHz divider.

Any of his kits still floating around?

Kent G8EMY

John Quarmby
 

I have used an ADA4851 as a line driver for 10MHz distribution on my tower mounted systems with ~50 ohms in series with the output to impedance match to the cable. It is available as a single, dual or quad SMD device.

73

John G3XDY

On 03/01/2020 20:23, Ed G3VPF wrote:
Many thanks for all the useful replies regarding the 10 MHz line driver. Perhaps a little more detail on my application is appropriate. I now have four portable systems for 23, 13, 6 and 3cms. As I have built each one I have built it as a standalone system with its own frequency reference so I now have an assortment of OCXO's of dubious origin and GPSDO's. I am now trying to integrate the four systems by using multi-band dish feeds and by reducing the number of support boxes. All four systems need a 10 MHz reference so I have invested in a high quality OCXO and now wish to feed it to all four systems. I am very space-limited and would like to put the system in the physical location of one of the GPSDO's. It means I have to build the unit into an identical box so the use of pre-built units is not appropriate.

The LM7171 has been suggested, but I tried this device driving 25MHz up a long piece of coax to the QO-100 LNB and found it was severely slew-rate limited. Changed to a BUF634 and this was OK. In this application the frequency is lower and the length of coax much less so the LM7171 may be OK. The BUF634 only has a gain of 0dB and in this case I need a gain of around 12dB so hence my quest for a suitable device.

I will follow-up some of the suggestions which may well be fruitful. Thanks once again for the assistance.

Ed, G3VPF IO80RQ

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Dennis Anderson via Groups.Io <g6ybc@...>
Sent: 03 January 2020 13:55
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] 10MHz buffer amplifier
 
I believe that SDR-Kits are selling some

Dennis G6YBC 




On Thursday, January 2, 2020, 10:14 pm, Neil Smith G4DBN <neil@...> wrote:

I have one of the 8-port kits still unbuilt, but I want to keep it to build on a special day. 

I already have one 4 port and one 8-port in use.  The 8-port was his first production upgrade board to turn a 4 into an 8.  They are by no means perfect, there is some port interaction and no transformer isolation.  When I boot my HP 8562A, it sends an output on the 10MHz port for a short time, which really messes up some of the other kit else connected to the same HUP box.

At this exact time I'm building a HUPrf e-field receive preamp and bias-tee kit.  I have seven more of those to build for a club project.

Sadly missed....

Neil G4DBN


On 02/01/2020 21:45, KENT BRITAIN wrote:
HUP had a kit for a 4 way 10 MHz divider.

Any of his kits still floating around?

Kent G8EMY