K1 - Problem

[Ken H]

Hi, with my K1-4;  serial #1951 I have the following symptoms/problems.  I sure will appreciate any help given.

I have completed the assembly and did the alignments and tests.  Everything seems to be working just fine except for the following - AND I have not been able to find where the C2A (120J) capacitor shown in the RF board parts list.  Anyone able to tell me where that goes?   Reference is made to this capacitor on page 27 at the bottom right where the C11 (1200J) capacitor is installed, but no location is given for C2 or C2A capacitor.

40 meter = 7 watts output
30 meters = 0.1 watt output
20 meters = 5 watts output
17 meters = 5 watts output

The receive seems to be good on 40, 20, and 17 meter bands.  30 meters is very weak receive.  With just this small amount of output on 30 mtrs, does this show the 18.100 crystal is working?

Voltage checks at D9 Anode = 0 vdc (spec calls for 4.3-4.6)
Voltage checks at D9 Cathode = 5.03 vdc (spec calls for 3.8-4.1)
Voltage checks at D10 Anode = 5.65 vdc (spec calls for <0.2)
Voltage checks at D10 Cathode = 5.03 vdc (spec calls for 3.8-4.1)
Voltage checks at D11 Anode = 5.65 vdc (spec calls for <0.2)
Voltage checks at D11 Cathode = 5.06 vdc (spec calls for 4.0-4.6)
Voltage checks at D13 Anode = 0.0 vdc (spec calls for 0.4-0.7)
Voltage checks at D13 Cathode = 5.65 vdc (spec calls for <0.2)

I am amazed how far off the voltages are with the radio working as well as it is  When I listen to the transmitted signal on the 756Pro, it sounds clean and clear.  Sidetone sound good.  All the menu options seem to work as they should.  If it wasn't for the low output on 30 mtrs and the freq problem in the next e-mail, I would think the radio was ok.

Thanks for any and all help,

ken H>
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[Don Wilhelm-3]

Ken,

Either C2 or C2A is to be installed on page 38 of the manual (at least that
is the page in Rev F).  The board location is below L1 and just above RP2. -
If you installed C2, then C2A will be left over.

On your 30 meter problem - you can try listening for the 18.1 MHz oscillator
on another receiver.  Do recheck all the soldering on your 4 band board to
be certain everything is well soldered and that there are no unsoldered
connections.  Try re-aligning on 30 meters - you should find a good peak.

For the transmit frequency problem, recheck the Transmit Offset Adjustment,
and then re-do the operating frequency calibration.

73,
Don W3FPR

----- Original Message -----

Hi, with my K1-4;  serial #1951 I have the following symptoms/problems.  I
sure will appreciate any help given.



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[Ken H]

Thank you Jim - I'll also post this to the group as well just to keep them informed about where I'm at with testing.  IF I can't get this thing aligned completely, I may have to resort to bothering you with it "next year" when I get back to Mobile.

I did the following tests and re-checked the transmitter offset adjustment again.  That didn't seem to change much of anything.  As the two tones came together, there was kind of a "waver" in the sound.  when I continued to move past that point, the waver would disappear, then appear again.  I then moved the adjustment between those two points.  Is that correct?

> a problem with the 30 Meter HetrodyeOscillator Crystal.  It sounds like it
> is not oscillating.  If you have a general coverage receiver you can tune to
> the freq of the crystal and see you can hear it.

I tuned my 756Pro with CW filter set to 100hz with a coax jumper connected to the antenna SO-239.  With the K1-4 just turned on, no antenna connected and in receive mode with other end of coax held close to J6, pin #4 I get:
40 meter band = 15,003.96Mhz with a nice tone (15.00 Crystal?)
30 meter band = 18,097.78 Mhz with a nice tone (18.100 Crystal?)
20 meter band = 21.996.83Mhz with a nice tone (22.00 Crystal?)
40 meter band = 26,046.64Mhz with a nice tone (26.05 Crystal?)

The 30 meter signal was as strong as the other bands, but I am surprised at the offset from the stated filter freq.  OR is this normal and why we must do the Freq offset calibration for each band?

Now when I transmit with the K1-4 into a dummy load (an old Health Cantenna) and tune in the signal on the 756Pro, I get the following:

K1 transmits at 7040.0 = 756Pro receives at 7040.67 (K1 receives same freq 756Pro transmits)
K1 transmits at 10,130.0 = 756Pro receives at 10,130.00 (but K1 receives 600 hz off.)
K1 transmits at 14,030.0 = 756Pro receives at 14,030.63 (K1 receives same freq 756Pro transmits)
K1 transmits at 18,090.0 = 756Pro receives at 18,090.62 (K1 receives same freq 756Pro transmits)

On 30 meters the K1-4 only transmits in the milliwatt range too small to see on my wattmeter.  The K1-4 seems to receive pretty good on 30 meters when connected to outside antenna.  A weak signal on the 756Pro is still received on the K1-4, but a bit weaker.  It the signal is received on the 756Pro at 10,30.00, the K1-4 will receive it about 10,130.6.  It really seems like the K1-4 is receiving ok on 30 meters, just no power output.

I also re-melted solder on all the L1-L2-L3 inductor wires and the capacitors around it.  I counted the number of turns on each of the inductors to be sure it was correct and checked the spacing around the torrid core.

Thank you for the help,

Ken



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