nHello,
Is there any modification advice document how to connect the Leo Bodnar GPSDO to the Kiwisdr ?

From a rough study of the kiwi design document, it seems the PCB is providing a connection point for a Hirose coaxial connector, where the GPSDO must be connected; As that connector is not included, one needs to solder it on the PCB, homebrewing...
But are there any other modification needed - interconnections/interruption to be done on the PCB ?
I guess also LPFs need to be done, as the kiwi is probably expecting a pure sinus signal. The LPF will then extract the base frequency of the Leo Bodnar to feed the kiwi correctly (my rough assumption...)

Is it possible to solder the connector by hand without sophisticated soldering system for PCB manufacturing ?
I have soldered by hand (some years ago) the original N2PK VNA (all SMD down to 602 size components. For that I used a very thin solderwire (0.5mm ?) and a sharp tip for my electronic solder station...
Has someone done the modification that way - any experience advice for succesful soldering ?
Good glasses with lights are available in my small lab... however my eyes are rather old in the meantime....:-(

What is the level of the GPSDO signal to provide ?
I have never tried : is it possible to run the Leo Bodnar (2 outputs version) headless - I mean without USB connector nor a computer connected, after initial set-up ?

With Gwyns findings on the new modes, it seems to me, that one should modifiy the kiwis and distribute the GPSDO signal to lock the kiwisdr for stability, rather than distributing GPS antenna cable. The internal 'normal' GPS mode will never achieve the stability needed anyway...

Thanks for some advice from the practicemen...

Ulli, ON5KQ

On Sep 1, 2022, at 12:37 PM, Edward (W3ENR / K3WRG) <manager@...> wrote:

I found a local club member who does surface mount soldering in his professional work to put the connector on the J5 pad. He offered to do it, so I can't offer any personal experience there.

Snapping the IPEX cables onto the connector soldered to the board was a bit tough for me.  They don't go on easily, and I was concerned that the amount of force I had to use to attach the cable would break the new connector off the board.  This did not happen, but be careful.

I have two mini-Bodnars (one output each). Both operate at the default (maximum) signal level (32mA). A simple RG316 SMA splitter cable has worked for me to feed a single Bodnar output to two Kiwis.

EH


On 9/1/22 11:43 AM, ON5KQ wrote:

nHello,

Is there any modification advice document how to connect the Leo Bodnar GPSDO to the Kiwisdr ?

From a rough study of the kiwi design document, it seems the PCB is providing a connection point for a Hirose coaxial connector, where the GPSDO must be connected; As that connector is not included, one needs to solder it on the PCB, homebrewing...

But are there any other modification needed - interconnections/interruption to be done on the PCB ?

I guess also LPFs need to be done, as the kiwi is probably expecting a pure sinus signal. The LPF will then extract the base frequency of the Leo Bodnar to feed the kiwi correctly (my rough assumption...)

Is it possible to solder the connector by hand without sophisticated soldering system for PCB manufacturing ?

I have soldered by hand (some years ago) the original N2PK VNA (all SMD down to 602 size components. For that I used a very thin solderwire (0.5mm ?) and a sharp tip for my electronic solder station...

Has someone done the modification that way - any experience advice for succesful soldering ?

Good glasses with lights are available in my small lab... however my eyes are rather old in the meantime....:-(

What is the level of the GPSDO signal to provide ?

I have never tried : is it possible to run the Leo Bodnar (2 outputs version) headless - I mean without USB connector nor a computer connected, after initial set-up ?

With Gwyns findings on the new modes, it seems to me, that one should modifiy the kiwis and distribute the GPSDO signal to lock the kiwisdr for stability, rather than distributing GPS antenna cable. The internal 'normal' GPS mode will never achieve the stability needed anyway...

Thanks for some advice from the practicemen...

Ulli, ON5KQ

Hi Ulli,
I am probably the least experienced here with soldering smd components- having only done it a dozen or so times by hand. That said I was able to achieve satisfactory results via microscope and fine tip soldering iron by hand, and very fine solder.
I used liquid flux and placed the u.fl connector on the board. When I flowed one tab, I made sure it was exactly where it needed to be then moved on.
I purchased 12” u.fl to sma cables, later found out the bodnar needed bnc for the clk output, so I used an adapter.
The cables are indeed a tight fit.
Just make sure you have the correct u.fl connectors and matched cable connectors.
This was the best I could do
image

On Sep 1, 2022, at 12:37 PM, Edward (W3ENR / K3WRG) <manager@...> wrote:

I found a local club member who does surface mount soldering in his professional work to put the connector on the J5 pad. He offered to do it, so I can't offer any personal experience there.

Snapping the IPEX cables onto the connector soldered to the board was a bit tough for me.  They don't go on easily, and I was concerned that the amount of force I had to use to attach the cable would break the new connector off the board.  This did not happen, but be careful.

I have two mini-Bodnars (one output each). Both operate at the default (maximum) signal level (32mA). A simple RG316 SMA splitter cable has worked for me to feed a single Bodnar output to two Kiwis.

EH


On 9/1/22 11:43 AM, ON5KQ wrote:

nHello,
Is there any modification advice document how to connect the Leo Bodnar GPSDO to the Kiwisdr ?

From a rough study of the kiwi design document, it seems the PCB is providing a connection point for a Hirose coaxial connector, where the GPSDO must be connected; As that connector is not included, one needs to solder it on the PCB, homebrewing...
But are there any other modification needed - interconnections/interruption to be done on the PCB ?
I guess also LPFs need to be done, as the kiwi is probably expecting a pure sinus signal. The LPF will then extract the base frequency of the Leo Bodnar to feed the kiwi correctly (my rough assumption...)

Is it possible to solder the connector by hand without sophisticated soldering system for PCB manufacturing ?
I have soldered by hand (some years ago) the original N2PK VNA (all SMD down to 602 size components. For that I used a very thin solderwire (0.5mm ?) and a sharp tip for my electronic solder station...
Has someone done the modification that way - any experience advice for succesful soldering ?
Good glasses with lights are available in my small lab... however my eyes are rather old in the meantime....:-(

What is the level of the GPSDO signal to provide ?
I have never tried : is it possible to run the Leo Bodnar (2 outputs version) headless - I mean without USB connector nor a computer connected, after initial set-up ?

With Gwyns findings on the new modes, it seems to me, that one should modifiy the kiwis and distribute the GPSDO signal to lock the kiwisdr for stability, rather than distributing GPS antenna cable. The internal 'normal' GPS mode will never achieve the stability needed anyway...

Thanks for some advice from the practicemen...

Ulli, ON5KQ