Q7, Q8, Q11 and Q13 are all now replaced, and everything seems to be working
normally again. Thanks everyone for all the help.
73,
Jeremy
VA3ZTF
JeremyJones wrote
> Yes that was an Alkaline battery. That makes me feel better about
> installing the new finals once they arrive. In the mean time
Yes that was an Alkaline battery. That makes me feel better about installing
the new finals once they arrive. In the mean time I have a KAT100 and
KPA100 to build.
Jeremy
Don Wilhelm-4 wrote
> Jeremy,
>
> That voltage is close to what I would expect from a new Lithium battery.
> If you are me
Jeremy,
That voltage is close to what I would expect from a new Lithium battery.
If you are measuring an Alkaline battery, then your voltmeter is a bit
on the high side.
So if Alkaline battery, then your 0.65 measurement is likely OK, but if
that battery is a Lithium type, the bias is a bit h
A new AA battery right from the package is giving me 1.615V on the fluke
meter. This is a newer K2 (#7405). I had some issues when building it
which caused me to go through a couple of sets of PA finals before I had to
send it to you to get sorted out. It was working great until now, so
hopefull
Jeremy,
Make a quick check on your voltmeter - measure a new Alkaline battery,
you should see quite close to 1.50 volts.
Are you making the measurement by using TUNE? If not, you should be.
Is this an older K2 with a trimpot at R60? If so, it should be turned
fully counterclockwise.
Check
I don't know how much over 0.64 volts is bad, but I am getting 0.656.
I didn't realize that a web reply was cutting off what I was replying to. I
always hit the reply button and assumed it included the original text.
Jeremy
Don Wilhelm-4 wrote
> Jeremy,
>
> A power reading of 0.1, 0.2 or 0.
Knut,
Yes, that made it through OK. I usually see posts through Nabble that
contain no reference information, and sometimes the subject line is not
relevant.
I was blaming the way Nabble works, but I guess that is not the issue.
Apparently the poster has a choice of leaving a bit of referenc
Hi Don,
I always use Nabble to reply to postings. Do you not see the response to
Jeremy below and then the rest is ped off?
AB2TC - Knut
Don Wilhelm-4 wrote
> Jeremy,
>
> Remove the tuner and you will not be bothered with the LowP messages.
> In fact when testing the base K2, you should remove
Jeremy,
A power reading of 0.1, 0.2 or 0.3 is only residual noise on the power
detection circuits. Since you do not have Q7 and Q8 installed, your
real power output is zero.
Yes, go ahead and change Q11 and Q13. That is not certain to change
anything, but it will do no harm.
A slightly low
With the tuner disconnected, I'm still getting 600mV at the base of Q8 while
doing a tune. The display on the radio shows power of 0.3.
--
View this message in context:
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Sent from the Elecraft mailing list archive at
Jeremy,
Remove the tuner and you will not be bothered with the LowP messages.
In fact when testing the base K2, you should remove the tuner and
operate the basic K2 into a dummy load.
Where are you measuring 600mV? That is one problem with replying using
Nabble, it strips off what you are re
I'm still getting 600mV and LowP during the tune, so it looks like I'll be
replacing Q11 and Q13 as well.
--
View this message in context:
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Sent from the Elecraft mailing list archive at Nabble.com.
_
Jeremy,
From those resistance readings, I would say you are OK.
If you have all except Q7 and Q8 installed, do a TUNE and re-check the
voltage on the base solder pads of Q7 or Q8. If you do not see a
voltage between 6.2 and 6.4 volts, replace Q11 and Q13 and retest before
you install Q7 and Q
So after reassembling everything minus Q7/8, resistance from ground to
collector pad for Q7/8 starts at 600k ohm then gradually drops down to 54k
ohm before reseting and spiking back up to 600k and dropping again. I
believe this would be a capacitor charging up and then biasing a transistor?
--
There is no indication on the cheap meter for an out of scale reading.
I've borrowed a Fluke meter from work, and after watching the capacitors
charge up, the resistance reading is 2.7k ohm. This is will all of the
resistors still connected as above. I'll reconnect them one by one and
check the
Jeremy,
I would tend to believe the reading on the 2000 ohm scale.
Look at the display in the 200 ohm scale and see if it shows a "+" to
the left - If so, that indicates overrange and you should switch to a
higher range.
I would also believe that the 20k and 200k scales are showing you
resista
Yes it is a digital multimeter, but I only paid about $10 for it.
What resistance should I be seeing. I have noticed some drastic variations
as I change the scale on my meter. The 200 ohm scale gives a reading of 91
ohms
2000 ohms scale reads 1500
20K scale reads 3.7
200k scale reads 10.7
What
Jeremy,
Yes, you should be doing the resistance checks with no power applied.
Inexpensive ohmmeter? Well, if it is a digital multimeter in resistance
mode, you should be OK, but i it is an analog VOM or VTVM, it may not be
showing you the real picture because the voltage may be sufficient to
I have lifted R45, RFC4, R74, R82 and R97, with only a slight increase from
70 ohms to 87 ohms after lifting RFC4. I'll continue troubleshooting
tomorrow by removing any capacitors connected to 12V.
I also want to confirm that I should be doing these resistance checks with
no power applied.
Als
Jeremy,
Leave them disconnected until you find the culprit.
Take notes of waht you have done if necessary so you can restore things
after you have found the problem.
73,
Don W3FPR
On 2/12/2014 8:46 PM, JeremyJones wrote:
Lifting one end of R45 still showed 70 ohms. Lifting one end of RFC4
i
Lifting one end of R45 still showed 70 ohms. Lifting one end of RFC4
increased to 87 ohms. I left the leg of R45 disconnected when taking this
measurement, and I want to confirm whether I should leave the components
disconnected as I go through, or reconnect them before moving on to the
next.
Th
Jeremy,
70 ohms is too low on the +12 volt power line, you should see a large
capacitor charging and the resistance should climb if all is normal.
1 volt on the base during a TUNE is too high, so plan to replace Q11 and
Q13 - they are included in the K2PAKIT.
Yes, static can be induced by win
With Q7/Q8 removed, the resistance from the Collector solder pad to ground on
both is 70 ohms.
Doing a "Tune" with Q7/Q8 removed results in 1.0V on the Base pads and a Low
P on the display. I do have the KAT2 installed, just in case this makes a
difference. This was done into a dummy load.
The
Jeremy,
One afterthought -- although Q7 and Q8 are the top suspects for your
problem, after removing them, check the resistance from the Q7/Q8
collector solder pads to ground. If it is still low, the problem is
something other than Q7 and Q8.
73,
Don W3FPR
-
Jeremy,
OK, Q7 and Q8 are 'toast', you might as well remove them.
With Q7 and Q8 removed, do a TUNE and measure the DC voltage at the
solder pads for the base of Q7 and Q8. The expected voltage is 0.60 to
0.64 volts. If it is out of that range, replace Q11 and Q13 too. Those
transistors co
jones9...@gmail.com
> To: elecraft@mailman.qth.net
> Subject: Re: [Elecraft] K2 Won't power on
>
> Q7 and Q8 both read 12.3 ohms from collector to ground.
>
> The symptoms definitely resemble blown finals, as I experienced the same
> thing when I was building the kit, includi
Q7 and Q8 both read 12.3 ohms from collector to ground.
The symptoms definitely resemble blown finals, as I experienced the same
thing when I was building the kit, including the over current tripping the
resettable fuse. I just didn't expect that from a receive only condition.
Jeremy
VA3ZTF
Jeremy,
I can't recall a "loud buzz" condition, but I would suspect the PA
transistors in the base K2.
First, check the resistance from the collectors of Q7 and Q8 to ground.
If it is quite low, the PA transistors are toast - get the K2PAKIT and
install Q7, Q8 as well as Q11 and Q13.
If the
> Date: Tue, 11 Feb 2014 16:44:25 -0800
> From: jjones9...@gmail.com
> To: elecraft@mailman.qth.net
> Subject: [Elecraft] K2 Won't power on
>
> So my K2, which has been running great for almost a year, no longer powers
> on. I had left it powered on and connected
So my K2, which has been running great for almost a year, no longer powers
on. I had left it powered on and connected via the serial cable to a
computer so that I could do PSK-31 contacts remotely while I was away from
home. Unfortunately I never got the chance, and upon my return home, my K2
was
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