K2 SSB adapter problem

[Lennart]

After I installed the K2 SSB adapter I get half or less power on all bands except 30 meter. On 20 almost nothing. SWR low through SGC239. Removed adapter and everything worked normal. Put the adapter back in and power is back to low level. It behaves like the SWR suddenly increased or SWR sense acts up.

I checked voltages on the adapter and I have some levels way out of spec. T1 and T2 0 ohms on all windings.

13,5 volts PS, 0.1W, LSB 80m, FL1, TX from "dot" on paddle. My meter is probably shows .03v low

        RX TX
U1-15 0.00 5.86    a bit low
U1-16 5.96 3.05    2.5 volts below spec
U1-17 5.96 4.12
U1-25 0.00 1.43

U2-5 0.47 0.47
U2-6 5.43 5.43
U2-8 5.96 3.05

I guess it comes from the U2-8 output being way too low, but I am not sure why. Same U2-8 levels on all bands, even on 30 where the otput is OK on "tune".

Everything looks OK on the adapter.

73
Lennart

[Don Wilhelm-4]

Lennart,

If you have transmit power problems in CW mode or TUNE, then the only
part of the SSB opyion board that could cause that condition is Q1, Q2,
Q3 and the associated components.

Look at the KSB2 board schematic near the bottom and you will see which
components need to be checked.

There is no explanation for a band dependency related to the KSB2
board.  It operates at the BFO and IF paths.

73,
Don W3FPR

Lennart wrote:

> After I installed the K2 SSB adapter I get half or less power on all bands
> except 30 meter. On 20 almost nothing. SWR low through SGC239. Removed
> adapter and everything worked normal. Put the adapter back in and power is
> back to low level. It behaves like the SWR suddenly increased or SWR sense
> acts up.
>
> I checked voltages on the adapter and I have some levels way out of spec. T1
> and T2 0 ohms on all windings.
>
> 13,5 volts PS, 0.1W, LSB 80m, FL1, TX from "dot" on paddle. My meter is
> probably shows .03v low
>
> RX TX
> U1-15 0.00 5.86    a bit low
> U1-16 5.96 3.05    2.5 volts below spec
> U1-17 5.96 4.12
> U1-25 0.00 1.43
>
> U2-5 0.47 0.47
> U2-6 5.43 5.43
> U2-8 5.96 3.05
>
> I guess it comes from the U2-8 output being way too low, but I am not sure
> why. Same U2-8 levels on all bands, even on 30 where the otput is OK on
> "tune".
>
> Everything looks OK on the adapter.
>
> 73
> Lennart
>  

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[n0jrn]

Lernart:

I had a similar problem with my K2  #6272.           Gary sent me a response
stating that T1  and  T2  could cause
a low power situation on the higher bands   IF   they were
switch or the turn count was wrong or bad solders ........

I checked all mine and found that I had all turns correct,  they were in the
correct location and all solder joints were good.

I expanded on what Gary told me and started checking all related components.
I found I had the wrong value in R10.    It was suppose to be 100 ohm and I
had put a 10K ohm resistor in that spot.

Correcting the resistor error corrected the problem.

Check you schematic and check all the components related to T1  and
T2..........

YMMV  but it's worth a look.

72           Jerry               N0JRN

On 4/13/2008 5:00:20 AM, Lennart ([hidden email]) wrote:
> After I installed the K2 SSB adapter I get half or less power on all

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[Don Wilhelm-4]

Jerry,

T1 and T2 are not in the path for CW or TUNE, so they are not high on
the list of suspects for Lernart's situation.

OTOH, if the low power is on SSB (but CW and TUNE are good), then T1 and
T2 would be the prime suspects.

73,
Don W3FPR

n0jrn wrote:

> Lernart:
>
> I had a similar problem with my K2  #6272.           Gary sent me a
> response stating that T1  and  T2  could cause
> a low power situation on the higher bands   IF   they were
> switch or the turn count was wrong or bad solders ........
>
> I checked all mine and found that I had all turns correct,  they were
> in the correct location and all solder joints were good.
>
> I expanded on what Gary told me and started checking all related
> components. I found I had the wrong value in R10.    It was suppose to
> be 100 ohm and I had put a 10K ohm resistor in that spot.
>
> Correcting the resistor error corrected the problem.
>
> Check you schematic and check all the components related to T1  and
> T2..........
>
> YMMV  but it's worth a look.
>
> 72           Jerry               N0JRN
>
> On 4/13/2008 5:00:20 AM, Lennart ([hidden email]) wrote:
>> After I installed the K2 SSB adapter I get half or less power on all
>

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[Lennart]

Don Wilhelm wrote

Lennart,

If you have transmit power problems in CW mode or TUNE, then the only
part of the SSB opyion board that could cause that condition is Q1, Q2,
Q3 and the associated components.

Look at the KSB2 board schematic near the bottom and you will see which
components need to be checked.

So I check on the schematic and there is a lot of "RP3" there... When I took the resistor RP5 and read "473" my brain must have locked up and I put the "473" resistor as RP3, Should have been at RP5. When I swapped RP3 and RP5 things were going a lot better :-) So it was indeed a component in that area, a very stupid component to make a mistake on. Those resistor networks does not exactly fall out by themselves once soldered. One hour later the board is in place and gives perfectly normal response now.

Thanks for telling me what components to look for mistakes on, saved me a lot of time.

Best 73,
Lennart

[Don Wilhelm-4]

Lennart,

I am glad to hear you found the problem source.
Things like that happen to all of us at one time or another.  Mark it up
to experience and go on with other things more important.

73,
Don W3FPR

Lennart wrote:

>
>
> So I check on the schematic and there is a lot of "RP3" there... When I took
> the resistor RP5 and read "473" my brain must have locked up and I put the
> "473" resistor as RP3, Should have been at RP5. When I swapped RP3 and RP5
> things were going a lot better :-) So it was indeed a component in that
> area, a very stupid component to make a mistake on. Those resistor networks
> does not exactly fall out by themselves once soldered. One hour later the
> board is in place and gives perfectly normal response now.
>
> Thanks for telling me what components to look for mistakes on, saved me a
> lot of time.
>
> Best 73,
> Lennart
>  

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