The MSR2000 Tx multiplier is 12x the channel element frequency if I remember
right, so the crystal fundamental would be 14.279167. 157.071 would be the
11x product if that's the case. Look for a similiar spur on the other side
of carrier. The exciter may be bad or not properly tuned, or it could be
something as simple as a grounding/shielding issue.
Been a while since I worked on a highband MSR2000, but I don't believe there
is an external filter (helical resonator type or otherwise) between the
exciter and the PA like there is on a Micor, so more than likely it's a
problem on the exciter board itself.
Is this station being operated within the design range?
--- Jeff WN3A
> -----Original Message-----
> From: [email protected]
> [mailto:[EMAIL PROTECTED] On Behalf Of Bill Photinos
> Sent: Thursday, January 17, 2008 1:15 PM
> To: [email protected]
> Subject: [Repeater-Builder] MSR2000 transmit spike
>
> I have a MSR2000 repeater that transmits on 171.350mhz. We are seeing
> a transmit spike at 157.072mhz. It is strong enough to break squelch
> 10+ blocks away with legible copy on the spike frequency. We
> disconnected the PA and connected the duplexer directly to
> the exciter.
> The spike seems to be coming from the exciter itself. Would
> anyone have
> any suggestions on where to look on the exciter board to fix
> this short
> of installing a notch filter between exciter & PA? I haven't yet
> checked across the band for other spikes with a spectrum
> analyzer but I
> fear there may be other spikes as well.
>
> Thanks for the help!
>
> Best Regards,
> Bill - W4RVN
>
>
>
>
>
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