XRef - 10MHz-Locked Reference Oscillator

[VK2ZRH]

We await with bated breath

73, Roger Harrison VK2ZRH

[VK4OE]

Greetings to all.

To possibly assist other experimenters/installers, I just thought I'd add three pics of the way I have installed my one of this interesting accessory for the FT-817. Due to the thickness of the die cast rear panel, I milled away a half a mm or so to allow enough thread to be exposed for connecting to this SMA. This also removed the unevenness caused by the 'ANT' writing above the SO-239 connector.

Cheers and 73,

--Doug Friend, VK4OE.

[VK3HZ]

Hi All,

Looks like there's a bit of a common thread here. I used an SMB connector that I picked up at a swapmeet. As Doug said, the back panel is fairly thick. I drilled the hole for the connector, then very carefully countersunk it on the inner side using a much larger drill bit until the connector sat in far enough for the nut to be screwed on from the outside:

XRef in FT-817

Of course, when drilling, be very careful not to get metal chips into the rig. I use a cordless drill at very low speed and with the rig inverted.

Regards,
Dave.

[VK3HZ]

I've created a new web page for the XRef including more of the test result plots.

You can find it at http://www.vk3hz.net/XRef/XRef_Home.html

Regards,
Dave.

[VK2XAX]

Hi Dave,

Here is some phase noise plots performed on my FT-817 at 432.1 Mhz

The values track well with what you have measured.

Tests done with OEM oscillator, xref by itself and the xref driven by a Trimble Thunderbolt.

regards

Tim

[VK5KK]

Hi All

Some photo's of XRef-FT installed in a FT857

There is just enough room to drill a hole for a SMA connector on the topside of the rear panel near to the external speaker socket as per the photo
below. The connector neatly sits just under the cover edge when re installed.

The heatsink is 6mm thick so a bit of challenge to mount a connector without having to counter sink the body. Luckily I have a supply of long F+F bulkhead SMA adapters
that were long enough to mount without having to counter sink the hole.

The body of the SMA partially covers the internal speaker connector on the PCB (2pin same as FT817) making it hard to plug in (but clears ok once installed). I have made up a short extension M+F speaker lead (not in photo) so the speaker lead can be plugged into a floating connector.

Cheers

David VK5KK

[VK4UH]

Hi all

I have just completed the installation of an Xref board in my 817

I used a bulkhead SMA socket with some silverplated microcoax already attached as per the example of others.

I have however noticed an "issue" which perhaps others have noticed

If I apply a 10 MHz reference from my GPS unit and switch on the 817 it locks perfectly. If I then disconnect the 10 MHz source the radio goes dead, which I understand is correct

If I switch on the 817 without the 10 MHz source connected but with the external coax lead still attached the radio "takes off" and goes into oscillation. Short the open end of the reference coax and the rig locks perfectly with its on board oscillator.

Remover the coax cable completely from the SMA socket and again the oscillator locks perfectly. Add a longer length to the 10 MHz coax and again all is stable.

So it seems some random lengths of coax left on the 10 MHz input may prevent the oscilator from working properly. A trap for young players!

Incdentally applying a 10 MHz signal when the radio is already working on its inernal oscillator again makes the radio go dead - I assume this too is expected?

I did ground the internal coax shield at the XRef board end even though the instructions did not confirm this either way. (ie it is grounded at both ends) was this the intended way?

A tremendous piece of work by all those concerned with its development, I am really pleased.

Cant wait for the boards tocome available for the TS2000

Kevin VK4UH Brisbane

[VK3HZ]

Hi Kevin,

Yes, if you connect or disconnect the external 10 MHz, you need to cycle power to restart the board. This minor inconvenience allowed a great simplification of the circuitry allowing it to all fit on the board!

And yes, you should ground the 10 MHz coax at the board end, to the ground strip running along the edge.

I haven't observed the issue to which you refer, despite using a variety of coax lengths during testing. However, I'll have a closer look.

Regards,
Dave.

[VK4UH]

Thanks David

How far away are boards for the TS2000 and the IC910?

I have just laid out the green and bought a new IC9100 with a 30.00 MHz local oscillator. Will there be a version for locking it too?

Kevin VK4UH

[VK3QI]

Kevin,

For the 30MHz oscillator there is an alternative solution.

http://g4hup.com/DFS30/DFS30%20TechMan.pdf

We are using 3 of his units on our Field Day 706 rigs with great success.

Pretty much the same sort of connection to the rig, but in this case it is a tripler circuit with appropriate filtering.

I would expect the performance to rival any offereings that XDK and HZ can come up with.

Like you, I am waiting for a couple of TS2000 models to get our 1296 signal "dead on".

Cheers

Peter VK3QI

[VK2GOM]

I've used the G4HUP solution on my old IC746, but there is another solution nearer to home... Minikits. They do a GALI-84 tripler/amp. This is currently what I use on my IC910 with a Rubidium source.

http://www.minikits.com.au/electronic-k ... i-84-30MHz

73 - Rob VK2GOM / GW0MOH

[VK3HZ]

I'm assuming you're getting the 10.066667 MHz from a programmable version of the FE-5680A? Have you checked the phase-noise performance?

More info: http://www.ka7oei.com/10_MHz_Rubidium_FE-5680A.html

[VK2XAX]

I'm assuming you're getting the 10.066667 MHz from a programmable version of the FE-5680A? Have you checked the phase-noise performance?

More info: http://www.ka7oei.com/10_MHz_Rubidium_FE-5680A.html

One of the many excellent articles on the FE5680, but as we have found.... not all FE5680's are created equal.

See our own experiments on the FE5680's here...

www.vklogger.com/forum/viewtopic.php?f=40&t=10180

I've done phase noise tests and harmonic tests on my 910, with and without RB, but I cant seem to find them, so I'll just have to do them again

regards

Tim

[VK3HZ]

Hi Kevin,

... it seems some random lengths of coax left on the 10 MHz input may prevent the oscillator from working properly.

I've tested with various lengths of coax and have been unable to duplicate your problem. If it is an issue for you, return the board and I'll ship a replacement.

I have observed that the FT-817 itself often does not recover to correct operation after having the reference frequency removed then replaced. Cycling power is the only answer.

Regards,
Dave
VK3HZ

[VK4EA]

Installing the xRef must of one of the easiest, least painful project I've done since contracting this microwave disease. Thanks David for this most useful addition to my 817.

[VK3HZ]

We've now completed development of the XRef Versatile. We are going through the process of adapting and testing them for different frequencies and levels required for different radios. We're also documenting the installation process.

The first release now available is for the Icom IC-910H pictured below.

XRef-VS installed in an IC-910H

There are two versions of the XRef Versatile:
- the XRef-VT with onboard TCXO. This completely replaces the radio's own reference oscillator with the TCXO being used when the external 10 MHz reference is not connected.
- the XRef-VS with onboard power switching. This is used when the radio's own reference is to be used when the external 10 MHz reference is not connected.

If the IC-910H is fitted with the optional CR-293 High Stability Crystal Unit, then it is recommended to use the XRef-VS so that the radio will fall back to the CR-293 when there is no 10 MHz connected.
If the radio is standard, then the choice is up to you. There have been varying reports on the stability of the standard oscillator. The XRef-VT should provide better fall-back stability but at a slightly higher cost.

One outcome from the redesign is that we've been able to reduce the cost and have passed this on to you.
For VK purchasers, the XRef-VT is $130 and the XRef-VS is $120, plus $3 postage for up to 3 units.

More details are here: http://www.vk3hz.net/XRef/XRef_Home.html (corrected)

If you are interested in the XRef Versatile, please contact me on xref@vk3hz.net

Regards,
David Smith
VK3HZ

[VK3BQ]

http://www.vk3hz.net/XRef/XRef_Home.html is the working link fyi.

just need a ic9100 version thanks

[VK4FLR]

Please let me know when you get to a FT847 mod
following with interest
73
Frank VK4FLR

[VK6OX]

....and a "final" version for TS590/TS2000!

[VK3HZ]

The TS-2000 is next in line, followed closely by the FT-847 (both being rigs that I own!)

Regards,
Dave.