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TOPIC: VFO output
#169
pcmathew2003
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VFO output 3 Years ago Karma: 0
Hi
Maximum rf output of the vfo is only 600mV.
I am using the 1mH choke supplied with the kit.Any suggestions?
 
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#170
vu3cav
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Gender: Male rajanimohan vu3cav vu3cav Location: New Delhi Originally from Begusarai (Bihar) Birthday: 09/05
Re:VFO output 3 Years ago Karma: 3
Hi Mathew,

The RF voltage seems low. Let me know the linearity of the voltage and the frequecy range. Also let me know if you are getting the Rf voltage after connecting to the RX & TX circuit. If not, the voltage is low.

Try changing the capacitor to .1 near 2N2222 in VFO and also change the feed back capacitor to bit lower value say 270pf or 220pf.

Will update you if you don't get the desired result.

Rajani
 
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#171
vu3plp
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Gender: Male rajeshvuham Location: Bhubaneswar
Re:VFO output 3 Years ago Karma: -5
Hi Mathew,

change C47 value up or down and increase C49 value (If you solder 220pf then increase up to 300pf)with adjustment of L6 in VFO section.

de
vu3plp
 
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vu3plp
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#181
pcmathew2003
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Re:VFO output 3 Years ago Karma: 0
Still having problem with vfo output.
Now the vfo output is 2.27V without loading.
I have a doubt about the position of C36 on the pcb. It is parallel to D10 and has remarkable effect on the frequency of oscillation and stability.
mtw
 
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#182
vu3plp
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Gender: Male rajeshvuham Location: Bhubaneswar
Re:VFO output 3 Years ago Karma: -5
Hi Mathew,

My ATS-1 VFO output is approx 2.20 Volt. C36 is ok.
Are you using R28 (L16)?

de
vu3plp
Bhubaneswar
 
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