VK Logger Ham Radio Forum Archive

Gday everyone,
My 10Mhz Distribution boards are now available

In some situations these boards can provided remarkable improvements!
10Mhz systems are often neglected due to "more important microwave stuff", unfortunately if a 10MHz reference is not clean it will greatly affect all of the associated equipment (especially PLL systems)

10MHz "ground loops", harmonics and feedback from other equipment can cause all sorts of issues! (This board can "Work Magic" on some systems )


Available, price is AUS$65 (and typically $7 postage within VK (padded box))

If interested please correspond by email, (to ease up the logger. ) (it also makes it easier for me to keep track of )
grumss@yahoo.com.au

And a photo!

VK3XDK wrote:...

Graham,

I looked at the PDF, but I did not find input Z.

Is it Hiz or 50+j0?

If it is 50+j0, I will take one as I think will address the issues discussed at http://vk1od.net/module/PllLdr/RefTerm.htm.

Thanks... Owen

Gday Owen,
Yes it is a 50R (50ohm) input, I probably should of mentioned it somewhere

I'll grab one please.

I would like one as well.

Email has been sent. I would like one as well Graham.
Thanks.

Looks like I am going to be busy!

could those interested please correspond by email (to ease the logger) (it is also a lot easier for me to keep track of the orders)
grumss@yahoo.com.au

Graham was displaying these at GippsTech 2013, and they look really neat.
BNCs poke through the rear (or front!) panel very easily for distribution.

Two more pictures. (Have been meaning to get these GippsTech images to Graham for his own use).

Hi Graeme

VK3XDK wrote:Looks like I am going to be busy!
could those interested please correspond by email (to ease the logger) (it is also a lot easier for me to keep track of the orders)
grumss@yahoo.com.au

Yes this will be a nice adjunct to any GPS or oven standard in a shack, had you considered any options for chaining them in series? In my case, I have a test bench with a Thunderbolt with a few bits of test gear that can take an ext 10MHz but now over the other side of the room I have an IC-910 with an xref in it that needs 10MHz, which is soon to be followed by a agile PLL for a microwave band. It would be good to be able to have 4 or 8 ports at the test bench (paralleled inputs as you described) and 4 ports another 5 metres away via a single feed.

From your measurements, Will the output level from an output port be too high to drive a down stream 4 port input?

Regards,
Peter, vk5pj

Hi peter,
The input section is a 50R (1206) load resistor followed by a 10K trimmer (parallel) , these should be fine up to about 250mW (24dbm)

It is just a case of adjusting the trimmer to suit the input level (and required output level) of each board in the chain.
If the boards are connected in series, (ie output of one to input of another) there is likely to be no adjustment in the second board needed.
The input attenuator has been pre-set so that 10dbm IN produces 10dbm OUT. (the boards 8db (or so) of amplification has been nulled by the attenuator)

Here is a quick schematic of the input section of the board.
It can be compared to a volume control on a music amplifier, it can be turned down to zero if needed.

VK3XDK wrote:Here is a quick schematic of the input section of the board.
It can be compared to a volume control on a music amplifier, it can be turned down to zero if needed.

Graham,

It seems to me that where one wanted 8 or 12 output ports, two or three boards could be stacked vertically, the input term R removed from all but one, and the inputs paralleled with a vertical header or real short wires.

Owen

Yes exactly right Owen.

although at low impedance (50R) i think that 10Mhz is fairly forgiving with "input leads"

Did everyone who sent an email get a reply?
sometimes (often) emails get blocked by spam filters

trick is to check spam folders frequently

Gday everyone,
The original lot sold-out very quickly (within a week!)

I have now got more available, price remains at $65 plus postage
Please email if interested (grumss@yahoo.com.au)