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K2 build - VCO control voltage 0 volts

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Harry Stone

K2 build - VCO control voltage 0 volts

My VCO control voltage is zero on 40,30, and 15 meters. All other bands
are within the normal range, all tests prior to these measurements passed.
When I try to run CAL PLL, I get info 232 even though I am on 40 meters.

What should I check first?

Thanks!
harry
KD0NFY

--
Have old memories and young hopes.
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Don Wilhelm-4

Re: K2 build - VCO control voltage 0 volts

Harry,

The thing in the VFO Range Select area that is common between 40, 30 and
15 meters is C73,
Check its value - it should be 47 pF (marked 470).

A low voltage at R30 indicates that there is not sufficient capacity in
the tuned circuit and the PLL/VCO is trying to increase the value of the
total capacity. That means if C73 is the correct value, check its
soldering and the soldering of relay K13 pin 8.

CAL PLL depends on having the 40 meter frequency range correct, so you
will not be able to do that procedure until you have the R30 voltage in
range on 40 meters (info 232 means the frequency read by the MCU is not
correct (yes there are other possible causes of info 232). The
alignment steps are sequential, so if one does not give correct results,
you cannot skip to the next one without encountering problems.

73,
Don W3FPR

On 10/26/2013 6:13 PM, Harry Stone wrote:
> My VCO control voltage is zero on 40,30, and 15 meters. All other bands
> are within the normal range, all tests prior to these measurements passed.
> When I try to run CAL PLL, I get info 232 even though I am on 40 meters.
>
> What should I check first?
>
>

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Harry Stone

Re: K2 build - VCO control voltage 0 volts

Don,
I know this isn't exactly your first rodeo, but that's still pretty
impressive. I have the wrong component installed at C73, I have a 4
<point> 7 pF instead of a 47 pF.

Bravo!

thanx,
harry

On Saturday, October 26, 2013, Don Wilhelm wrote:

> Harry,
>
> The thing in the VFO Range Select area that is common between 40, 30 and
> 15 meters is C73,
> Check its value - it should be 47 pF (marked 470).
>
> A low voltage at R30 indicates that there is not sufficient capacity in
> the tuned circuit and the PLL/VCO is trying to increase the value of the
> total capacity. That means if C73 is the correct value, check its
> soldering and the soldering of relay K13 pin 8.
>
> CAL PLL depends on having the 40 meter frequency range correct, so you
> will not be able to do that procedure until you have the R30 voltage in
> range on 40 meters (info 232 means the frequency read by the MCU is not
> correct (yes there are other possible causes of info 232). The alignment
> steps are sequential, so if one does not give correct results, you cannot
> skip to the next one without encountering problems.
>
> 73,
> Don W3FPR
>
>
> On 10/26/2013 6:13 PM, Harry Stone wrote:
>
>> My VCO control voltage is zero on 40,30, and 15 meters. All other bands
>> are within the normal range, all tests prior to these measurements passed.
>> When I try to run CAL PLL, I get info 232 even though I am on 40 meters.
>>
>> What should I check first?
>>
>>
>>
>

--
Have old memories and young hopes.
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Don Wilhelm-4

Re: K2 build - VCO control voltage 0 volts

Harry,

You are welcome, enjoy the build. If you have problems, we are usually
available.
Yes, I have been "around the block" with the K2 a few times!

The question that may remain is - "Now where did I put that 47 pF
capacitor?" Have fun:-) .
BTW, the only 4.7 pF capacitor in the K2 RF Board belongs at the C6
location.
There are 47 pF capacitors at C20, C24, C73 and C203 - the parts list is
a good tool for deciphering misplaced capacitors.

73,
Don W3FPR

On 10/26/2013 8:15 PM, Harry Stone wrote:
> Don,
> I know this isn't exactly your first rodeo, but that's still pretty
> impressive. I have the wrong component installed at C73, I have a 4
> <point> 7 pF instead of a 47 pF.
>
>

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Harry Stone

Re: K2 build - VCO control voltage 0 volts

In reply to this post by Harry Stone

Well I spoke too soon. I replaced that capacitor and now I have 0 volts on
every band. Any thoughts?

thanx,
harry

On Saturday, October 26, 2013, Harry Stone wrote:

> Don,
> I know this isn't exactly your first rodeo, but that's still pretty
> impressive. I have the wrong component installed at C73, I have a 4
> <point> 7 pF instead of a 47 pF.
>
> Bravo!
>
> thanx,
> harry
>
>
>
> On Saturday, October 26, 2013, Don Wilhelm wrote:
>
>> Harry,
>>
>> The thing in the VFO Range Select area that is common between 40, 30 and
>> 15 meters is C73,
>> Check its value - it should be 47 pF (marked 470).
>>
>> A low voltage at R30 indicates that there is not sufficient capacity in
>> the tuned circuit and the PLL/VCO is trying to increase the value of the
>> total capacity. That means if C73 is the correct value, check its
>> soldering and the soldering of relay K13 pin 8.
>>
>> CAL PLL depends on having the 40 meter frequency range correct, so you
>> will not be able to do that procedure until you have the R30 voltage in
>> range on 40 meters (info 232 means the frequency read by the MCU is not
>> correct (yes there are other possible causes of info 232). The alignment
>> steps are sequential, so if one does not give correct results, you cannot
>> skip to the next one without encountering problems.
>>
>> 73,
>> Don W3FPR
>>
>>
>> On 10/26/2013 6:13 PM, Harry Stone wrote:
>>
>>> My VCO control voltage is zero on 40,30, and 15 meters. All other bands
>>> are within the normal range, all tests prior to these measurements
>>> passed.
>>> When I try to run CAL PLL, I get info 232 even though I am on 40
>>> meters.
>>>
>>> What should I check first?
>>>
>>>
>>>
>>
>
> --
> Have old memories and young hopes.
>

Don Wilhelm-4

Re: K2 build - VCO control voltage 0 volts

Harry,

That is quite strange. I would examine your work carefully,
particularly looking for lifted solder pads and/or solder bridges.

80 meters should have only C72 in the circuit. You should trace the VFO
range select path with an ohmmeter by following the path in the
schematic (checking for continuity) from K15 pin 3 through relays K15,
K14, and K13 to C72. Relays K15 and K14 should follow the path shown by
the closed contacts on the schematic while relay K13 should be "set"
which means continuity between pins 3 and 4.

73,
Don W3FPR

On 10/26/2013 9:09 PM, Harry Stone wrote:

> Well I spoke too soon. I replaced that capacitor and now I have 0 volts on
> every band. Any thoughts?
>
> thanx,
> harry
>
>
>
>
> On Saturday, October 26, 2013, Harry Stone wrote:
>
>> Don,
>> I know this isn't exactly your first rodeo, but that's still pretty
>> impressive. I have the wrong component installed at C73, I have a 4
>> <point> 7 pF instead of a 47 pF.
>>
>> Bravo!
>>
>> thanx,
>> harry
>>
>>
>>
>> On Saturday, October 26, 2013, Don Wilhelm wrote:
>>
>>> Harry,
>>>
>>> The thing in the VFO Range Select area that is common between 40, 30 and
>>> 15 meters is C73,
>>> Check its value - it should be 47 pF (marked 470).
>>>
>>> A low voltage at R30 indicates that there is not sufficient capacity in
>>> the tuned circuit and the PLL/VCO is trying to increase the value of the
>>> total capacity. That means if C73 is the correct value, check its
>>> soldering and the soldering of relay K13 pin 8.
>>>
>>> CAL PLL depends on having the 40 meter frequency range correct, so you
>>> will not be able to do that procedure until you have the R30 voltage in
>>> range on 40 meters (info 232 means the frequency read by the MCU is not
>>> correct (yes there are other possible causes of info 232). The alignment
>>> steps are sequential, so if one does not give correct results, you cannot
>>> skip to the next one without encountering problems.
>>>
>>> 73,
>>> Don W3FPR
>>>
>>>
>>> On 10/26/2013 6:13 PM, Harry Stone wrote:
>>>
>>>> My VCO control voltage is zero on 40,30, and 15 meters. All other bands
>>>> are within the normal range, all tests prior to these measurements
>>>> passed.
>>>> When I try to run CAL PLL, I get info 232 even though I am on 40
>>>> meters.
>>>>
>>>> What should I check first?
>>>>
>>>>
>>>>
>> --
>> Have old memories and young hopes.
>>
>

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Harry Stone

Re: K2 build - VCO control voltage 0 volts

Strange indeed, and here is why, when I was messing with it just now
measuring again, I laid my arm across the case and then I got voltage.
Somewhere I had something shorting against the case.

I'm back on track now, VCO voltage is in spec for every band. CAL PLL is
running now. When it's done I will double check the bottom of the RF board
to make sure I don't have something sticking up too high.

Thanks again!
harry

On Saturday, October 26, 2013, Don Wilhelm wrote:

> Harry,
>
> That is quite strange. I would examine your work carefully, particularly
> looking for lifted solder pads and/or solder bridges.
>
> 80 meters should have only C72 in the circuit. You should trace the VFO
> range select path with an ohmmeter by following the path in the schematic
> (checking for continuity) from K15 pin 3 through relays K15, K14, and K13
> to C72. Relays K15 and K14 should follow the path shown by the closed
> contacts on the schematic while relay K13 should be "set" which means
> continuity between pins 3 and 4.
>
> 73,
> Don W3FPR
>
> On 10/26/2013 9:09 PM, Harry Stone wrote:
>
>> Well I spoke too soon. I replaced that capacitor and now I have 0 volts
>> on
>> every band. Any thoughts?
>>
>> thanx,
>> harry
>>
>>
>>
>>
>> On Saturday, October 26, 2013, Harry Stone wrote:
>>
>> Don,
>>> I know this isn't exactly your first rodeo, but that's still pretty
>>> impressive. I have the wrong component installed at C73, I have a 4
>>> <point> 7 pF instead of a 47 pF.
>>>
>>> Bravo!
>>>
>>> thanx,
>>> harry
>>>
>>>
>>>
>>> On Saturday, October 26, 2013, Don Wilhelm wrote:
>>>
>>> Harry,
>>>>
>>>> The thing in the VFO Range Select area that is common between 40, 30 and
>>>> 15 meters is C73,
>>>> Check its value - it should be 47 pF (marked 470).
>>>>
>>>> A low voltage at R30 indicates that there is not sufficient capacity in
>>>> the tuned circuit and the PLL/VCO is trying to increase the value of the
>>>> total capacity. That means if C73 is the correct value, check its
>>>> soldering and the soldering of relay K13 pin 8.
>>>>
>>>> CAL PLL depends on having the 40 meter frequency range correct, so you
>>>> will not be able to do that procedure until you have the R30 voltage in
>>>> range on 40 meters (info 232 means the frequency read by the MCU is not
>>>> correct (yes there are other possible causes of info 232). The
>>>> alignment
>>>> steps are sequential, so if one does not give correct results, you
>>>> cannot
>>>> skip to the next one without encountering problems.
>>>>
>>>> 73,
>>>> Don W3FPR
>>>>
>>>>
>>>> On 10/26/2013 6:13 PM, Harry Stone wrote:
>>>>
>>>> My VCO control voltage is zero on 40,30, and 15 meters. All other
>>>>> bands
>>>>> are within the normal range, all tests prior to these measurements
>>>>> passed.
>>>>> When I try to run CAL PLL, I get info 232 even though I am on 40
>>>>> meters.
>>>>>
>>>>> What should I check first?
>>>>>
>>>>>
>>>>>
>>>>> --
>>> Have old memories and young hopes.
>>>
>>>
>>
>

Don Wilhelm-4

Re: K2 build - VCO control voltage 0 volts

Harry,

Make certain you have the bottom cover in place when running CAL PLL -
yes, it does make a difference!
If you did it with the bottom cover off, no harm, just do it again.

73,
Don W3FPR

On 10/26/2013 10:12 PM, Harry Stone wrote:

> Strange indeed, and here is why, when I was messing with it just now
> measuring again, I laid my arm across the case and then I got voltage.
> Somewhere I had something shorting against the case.
>
> I'm back on track now, VCO voltage is in spec for every band. CAL PLL is
> running now. When it's done I will double check the bottom of the RF board
> to make sure I don't have something sticking up too high.
>
> Thanks again!
> harry
>
>
> On Saturday, October 26, 2013, Don Wilhelm wrote:
>
>> Harry,
>>
>> That is quite strange. I would examine your work carefully, particularly
>> looking for lifted solder pads and/or solder bridges.
>>
>> 80 meters should have only C72 in the circuit. You should trace the VFO
>> range select path with an ohmmeter by following the path in the schematic
>> (checking for continuity) from K15 pin 3 through relays K15, K14, and K13
>> to C72. Relays K15 and K14 should follow the path shown by the closed
>> contacts on the schematic while relay K13 should be "set" which means
>> continuity between pins 3 and 4.
>>
>> 73,
>> Don W3FPR
>>
>> On 10/26/2013 9:09 PM, Harry Stone wrote:
>>
>>> Well I spoke too soon. I replaced that capacitor and now I have 0 volts
>>> on
>>> every band. Any thoughts?
>>>
>>> thanx,
>>> harry
>>>
>>>
>>>
>>>
>>> On Saturday, October 26, 2013, Harry Stone wrote:
>>>
>>> Don,
>>>> I know this isn't exactly your first rodeo, but that's still pretty
>>>> impressive. I have the wrong component installed at C73, I have a 4
>>>> <point> 7 pF instead of a 47 pF.
>>>>
>>>> Bravo!
>>>>
>>>> thanx,
>>>> harry
>>>>
>>>>
>>>>
>>>> On Saturday, October 26, 2013, Don Wilhelm wrote:
>>>>
>>>> Harry,
>>>>> The thing in the VFO Range Select area that is common between 40, 30 and
>>>>> 15 meters is C73,
>>>>> Check its value - it should be 47 pF (marked 470).
>>>>>
>>>>> A low voltage at R30 indicates that there is not sufficient capacity in
>>>>> the tuned circuit and the PLL/VCO is trying to increase the value of the
>>>>> total capacity. That means if C73 is the correct value, check its
>>>>> soldering and the soldering of relay K13 pin 8.
>>>>>
>>>>> CAL PLL depends on having the 40 meter frequency range correct, so you
>>>>> will not be able to do that procedure until you have the R30 voltage in
>>>>> range on 40 meters (info 232 means the frequency read by the MCU is not
>>>>> correct (yes there are other possible causes of info 232). The
>>>>> alignment
>>>>> steps are sequential, so if one does not give correct results, you
>>>>> cannot
>>>>> skip to the next one without encountering problems.
>>>>>
>>>>> 73,
>>>>> Don W3FPR
>>>>>
>>>>>
>>>>> On 10/26/2013 6:13 PM, Harry Stone wrote:
>>>>>
>>>>> My VCO control voltage is zero on 40,30, and 15 meters. All other
>>>>>> bands
>>>>>> are within the normal range, all tests prior to these measurements
>>>>>> passed.
>>>>>> When I try to run CAL PLL, I get info 232 even though I am on 40
>>>>>> meters.
>>>>>>
>>>>>> What should I check first?
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>> Have old memories and young hopes.
>>>>
>>>>