http://elecraft.85.s1.nabble.com/K3-Manual-change-suggestion-tp2479552p2491997.html
50% off and 50% on. This is the weight to which I keep my keyer
adjusted, and after sending that way for 45 years, I'm used to it.
33% on and 67% off. The idea of the tuning pulser is to adjust the
a hand on the key) and tuning. Then to revert to normal sending, I reset
and then have at it with my newly retuned amplifier. Note however that
hand on the key and twiddling the knobs on the amplifier with the other.
logger preempts the manual controls on the keyer. That means that in
get my tuning pulses with a single flip of the switch. In addition, both
done non-trivially faster. Finally, to get back to normal sending, I
box. This seems a small price to pay to greatly streamline the tuning
> Steve,
>
> If you recall, it takes about 3 dot intervals (at 20 to 25 wpm) for
> the K2 to come up to the requested power after a band change, so what
> you are seeing is the result of your short pulses with longer
> intervals in between. The K2 power controls may not have time to
> react with the short pulses.
>
> Out of curiosity, why are you not just sending a string of dots? It
> seems the 'pulser' is a device that could be used for those who do not
> have keyers.
>
> 73,
> Don W3FPR
>
> Stephen W. Kercel wrote:
>> Don:
>>
>> I'm glad to hear from you on this. I talked to Scott at Elecraft
>> earlier in the day, and he said that he had never heard of anyone
>> using a tuning pulser with a K2, but that if anyone would understand
>> the possible quirks it would be you.
>>
>> In addition to the "one bar less than normal keying," I have
>> discovered another quirk. If I change bands, and then try to run the
>> pulser, the transmitter does not key. I hear the side tone, but the
>> K2 power meter shows no bars. Also, the peak reading Watt meter in
>> series with my dummy load shows no RF output. I can remedy the
>> problem by reverting to the regular keyer and tweaking the power
>> level between QRP and QRO levels. Somehow this seems to reset
>> something in the rig. Once it transmits at regular keying speeds, if
>> I subsequently go to the tuning pulser, then the K2 will transmit the
>> pulses.
>>
>> I have not yet looked at the RF output on a scope. What I have
>> noticed is that once the transmitter does turn on, the peak reading
>> Watt meter in series with the dummy load gives me about the same peak
>> reading both for the pulser and normal keying.
>>
>> These various quirks do suggest to me that the the 12 ms "on"
>> interval is too short for the K2 to respond properly. Thus, your
>> suggestion of doubling the "on" interval sounds like a good
>> possibility for sidestepping these quirky behaviors. Both the "on"
>> and "off" durations are determined by a 0.1 uF capacitor in the
>> timing circuit of the pulser. If I change the capacitor to 0.18 uF
>> (values of 0.2 uF seem hard co come by), it would change the "on"
>> interval to 22 ms and preserve the 33% duty cycle.
>>
>> Unfortunately, the local Radio Shack does not carry these values, and
>> I'll need to order a new capacitor from Mouser. Thus, it will be a
>> few days before I can give this modification a try.
>>
>> I'll let you know how it turns out.
>>
>> BTW, for those who are curious, the Web page describing the pulser is
>>
>>
http://www.somis.org/D-a-09.GIF>>
>> The version that I built is the one transistor version.
>> TXN & 73,
>>
>> Steve Kercel
>> AA4AK
>>
>>
>> Don Wilhelm wrote:
>>
>>> Steve,
>>>
>>> I have not yet seen an answer on the reflector, so I will offer some
>>> comments. First, I do not think your pulser will hurt the K2 in any
>>> way.
>>> Secondly, I am at a loss to know why you do not see as many bars in
>>> the K2 LED display as you do in TUNE. The bargraph is relatively
>>> fast responding and should indicate the power level being
>>> transmitted. It may be that your pulser ON duration is too short
>>> and it causes a 'flicker' in the display that is not seen by the eye.
>>> It would be interesting to see what an oscilloscope connected across
>>> the K2 output would reveal (the oscilloscope display would react in
>>> even less time than the bargraph).
>>>
>>> So, bottom line, you may be seeing a natural result of the pulser ON
>>> time rather than an actual fault of the K2. Is there an easy way to
>>> double the ON time for your pulser? I find it hard to believe that
>>> 24 ms of ON time would cause any problems for your amplifier - it
>>> certainly would not pose any problems for the K2.
>>>
>>> 73,
>>> Don W3FPR
>>>
>>>
>>> Stephen W. Kercel wrote:
>>>
>>>> Elecrafters:
>>>>
>>>> I built a tuning pulser to use with my K2/100 to tune an external
>>>> linear amplifier. The pulser is the AG6K design. The pulse is 12 ms
>>>> on and 24 ms off, and repeats about 28 times per second. This is
>>>> (by design) much faster than the normal 25 wpm or so keying out of
>>>> the keyer.
>>>>
>>>> The interface between the pulser and the K2 is a 2N2222 NPN
>>>> transistor used as a switch. The key line to the K2 is connected to
>>>> the collector of the transistor (nothing else is connected to the
>>>> collector), the switching data comes in through the base, and the
>>>> emitter is grounded both to the ground side of the pulser circuit
>>>> and the ground side of the keying line back to the K2.
>>>>
>>>> I notice what seems to me to be an odd phenomenon when I key the K2
>>>> with the pulser. When I first switch on the pulser, the power level
>>>> in the little LED power meter on the K2 shows the same power level
>>>> as I get in normal keying. However, after the first instant, the
>>>> power level indication drops one bar lower (and then stays there as
>>>> long as the pulser is on) than the power level indication under
>>>> normal keying. This effect occurs independent of the power level
>>>> that I set. It happens with the K2's 100 Watt amplifier both in and
>>>> out.
>>>>
>>>> Is this simply an artifact of the metering circuit caused by the
>>>> peculiar duty cycle of the pulser?
>>>>
>>>> Most critically, will it harm the K2?
>>>>
>>>> Should I do as one alternative keying scheme shows, and use the
>>>> transistor to key a reed relay and use the reed relay (which would
>>>> simply hard short the K2 keying line on key down) to key the K2?
>>>>
>>>> TNX & 73,
>>>>
>>>> Steve Kercel
>>>> AA4AK
>>>>
>>>>
>>>> ______________________________________________________________
>>>> Elecraft mailing list
>>>> Home:
http://mailman.qth.net/mailman/listinfo/elecraft>>>> Help:
http://mailman.qth.net/mmfaq.htm>>>> Post: mailto:
[hidden email]
>>>>
>>>> This list hosted by:
http://www.qsl.net>>>> Please help support this email list:
http://www.qsl.net/donate.html>>>> ------------------------------------------------------------------------
>>>>
>>>>
>>>>
>>>> No virus found in this incoming message.
>>>> Checked by AVG - www.avg.com Version: 8.0.237 / Virus Database:
>>>> 270.11.13/2001 - Release Date: 03/14/09 06:54:00
>>>>
>>>>
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home:
http://mailman.qth.net/mailman/listinfo/elecraft>> Help:
http://mailman.qth.net/mmfaq.htm>> Post: mailto:
[hidden email]
>>
>> This list hosted by:
http://www.qsl.net>> Please help support this email list:
http://www.qsl.net/donate.html>> ------------------------------------------------------------------------
>>
>>
>> No virus found in this incoming message.
>> Checked by AVG - www.avg.com Version: 8.0.237 / Virus Database:
>> 270.11.15/2004 - Release Date: 03/16/09 07:04:00
>>
>>
>