K2: Update on 160 problem and looking for some help with K2IO

[Jess Gypin]

Got the problem with 160 fixed. I did not solder the pin that turned on the
160 relays in the KPA100.

On the K2IO problem.
Here are some voltage measurements that I took. I am not sure that the
measurements are correct. I am also looking at the schematic for the K2IO
section of the KPA 100. The /K2TX and /K2RX look ok at pin 11 and 12 of U4,
the MAX1406. However I am not sure of the voltage at pin 5 and 6 outputs.
Could someone clue me in to what the voltages measure on a KPA 100 that is
working or a K2IO? I have pinged Gary Surrency on this and am waiting for
his reply.


On pin 11 and 12 going into the MAX1406 from the K2, I measure 5V when
static. I measure -24 VDC on pin 5 and 0 VDC on pin 6 when static. This is
with no serial cable connected and the port option turned off. I am pretty
sure that the -24 on pin 5 is not good.

With the port on and the serial cable connected, I get -5.39 VDC on pin 6
and -24 VDC on pin 5. I have 4.96 VDC on 11 and 12. This is on U4, the MAX
1402. I also get the same measurements at the AUXIO port on either side of
the inductors, so I know that they are not open or shorted. It is also worth
noting that pin 8, the High Voltage Bias Supply is also at -24VDC. This is
the only source getting on to pin 5 that I can find.

When I activate the K24U program, the voltage change. I get 3 VDC and 2.5
VAC on pin 11. I also get about the same on pin 12, so it looks like the
levels coming from /K2TX and /K2RX are good.  I get 3.6 VDC and about 3.1 AC
on pin 6. BUT I get -9.86 VDC and 17.8 VAC on pin 5. This would indicate to
me that the voltage on pin 5 is way too high and that is why I can send
commands to the K2 and get them to work most of the time, and not get any
receive data at the PC. The commands that I send from the PC only work part
of the time. I have to send and resend to get the rig to do anything. I am
also not getting any receive data as far as the displays, VFO, nothing. I
have checked all of the cables, wires, inductors at RFC6,7 and 8. I get the
same voltage measurements at either side of the chokes mentioned. They all
check good with an ohmmeter, so I am assuming that since the voltage is
being passed to the serial connector on the output side that all is well.

I get 6M Ohm to ground at pin 5, 2.5M ohm to ground at 6. I have 2.87 M ohm
to ground at pin 8 and 10M ohm between pin 5 and 8, so it does not really
look shorted to me internally.

If someone could measure the voltages on a working unit, that would really
help me at this point.


Jess AE0CW



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[Don Wilhelm-3]

Jess,

The -24 volts on U4 pin 5 is within the range permitted by the RS232
standard and should be OK.  The RS232 signalling voltages are stated as:

"Signal State Voltage Assignments - Voltages of -3v to -25v with respect to
signal ground (pin 7) are considered logic '1' (the marking condition),
whereas voltages of +3v to +25v are considered logic '0' (the spacing
condition). The range of voltages between -3v and +3v is considered a
transition region for which a signal state is not assigned."

>From your voltage measurements, I can detect nothing really bad, but it is
difficult to tell just from DC and AC voltage readings.  You really need a
'scope on the TXD and RXD signals (U4 pins 5 and 6) to know for certain.  To
determine proper operation, we must know if the dynamic signals ever get
above the +3 volt level (and they will only be there for the duration of a
bit time).   AC measurements will only be meaningful if the data stream is
known.  The fact that you have an AC component on the signalling lines is an
indicator that they have a possibility for working.

One thing that may help you is knowing the source (and direction) of each of
the signals - the computer port sources the TXD signal and will determine
the levels at U4 pin 6 ,The KPA100 I/O port only reads this line level and
provides it as a TTL compatible level (<0.8 volts and >2.0v).  The RXD
signal is sourced by KPA100 U4 (in response to the TTL level input at pin
12) and appears as an RS232 level at U4 pin 5.

You may have a problem with your computer port.  Have you tried another
computer?  Some (particularly laptops) do not rigidly adhere to the RS232
switching levels, and will work in most cases, but not all.  To simplify
things, use Hyperterminal (or equivalent) to provide predictable data
streams for debugging rather than attempting to use a logging or rig control
program which has a variety of data streams.  Again, a 'scope may be the
only good tool to use in determining whether the RS-232 levels are correct.

73,
Don W3FPR

> -----Original Message-----
>
> On the K2IO problem.
> Here are some voltage measurements that I took. I am not sure that the
> measurements are correct. I am also looking at the schematic for the K2IO
> section of the KPA 100. The /K2TX and /K2RX look ok at pin 11 and
> 12 of U4,
> the MAX1406. However I am not sure of the voltage at pin 5 and 6 outputs.
> Could someone clue me in to what the voltages measure on a KPA 100 that is
> working or a K2IO? I have pinged Gary Surrency on this and am waiting for
> his reply.
>
>
> On pin 11 and 12 going into the MAX1406 from the K2, I measure 5V when
> static. I measure -24 VDC on pin 5 and 0 VDC on pin 6 when static. This is
> with no serial cable connected and the port option turned off. I am pretty
> sure that the -24 on pin 5 is not good.
>
> With the port on and the serial cable connected, I get -5.39 VDC on pin 6
> and -24 VDC on pin 5. I have 4.96 VDC on 11 and 12. This is on U4, the MAX
> 1402. I also get the same measurements at the AUXIO port on either side of
> the inductors, so I know that they are not open or shorted. It is
> also worth
> noting that pin 8, the High Voltage Bias Supply is also at -24VDC. This is
> the only source getting on to pin 5 that I can find.
>
> When I activate the K24U program, the voltage change. I get 3 VDC and 2.5
> VAC on pin 11. I also get about the same on pin 12, so it looks like the
> levels coming from /K2TX and /K2RX are good.  I get 3.6 VDC and
> about 3.1 AC
> on pin 6. BUT I get -9.86 VDC and 17.8 VAC on pin 5. This would
> indicate to
> me that the voltage on pin 5 is way too high and that is why I can send
> commands to the K2 and get them to work most of the time, and not get any
> receive data at the PC. The commands that I send from the PC only
> work part
> of the time. I have to send and resend to get the rig to do anything. I am
> also not getting any receive data as far as the displays, VFO, nothing. I
> have checked all of the cables, wires, inductors at RFC6,7 and 8.
> I get the
> same voltage measurements at either side of the chokes mentioned. They all
> check good with an ohmmeter, so I am assuming that since the voltage is
> being passed to the serial connector on the output side that all is well.
>
> I get 6M Ohm to ground at pin 5, 2.5M ohm to ground at 6. I have
> 2.87 M ohm
> to ground at pin 8 and 10M ohm between pin 5 and 8, so it does not really
> look shorted to me internally.
>
> If someone could measure the voltages on a working unit, that would really
> help me at this point.
>
>
> Jess AE0CW
>
>

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