[hpsdr] external 10MHz reference input

[H.A.Meijer]

Hi Tokio,

I'm measuring at the circuit,  the signal coming from the internal 10MHz 
is a nice square wave,
but when put on the external 10MHz (+13dBm 1V-tt @50Ohm sinus wave) it's 
not a nice square wave coming out
from the 2 stage buffer, just some top flatting at one site.
When I lowering the external 10MHz with an 20dB attenuator, this change 
to a 2V tt sinus wave and no locking at all.
So this could means that, a) I need bigger signal from my external 10MHz or
                                       b) I can try to modify some more 
this 2 stage buffer for better square-wave.
Yes, when using the external 10Mhz the internal osc is switched off 
completely, by removing the psu jumper and output from the osc.

Thanks

Bert
>
>
> Hi Bert,
>
> I had the same problem with an external clock 10MHz a couple of months 
> ago.
> With the help of Phil, VK6APH, I changed the value of the famous R141 
> to 50 ohm. It cleared the problem for my case. Please make sure that 
> the internal clock is stopped by the jumper and look at the the clock 
> wave just after the wave conversion circuit by oscilloscope. I hope it 
> will help you.
>
> Tokio
> JA1CCA
>
> 2013/05/18 16:58?"H.A.Meijer" <meijer.ha at home.nl 
> <mailto:meijer.ha at home.nl>> ??????:
>
>

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