Adam,
You cite 70 to 80 Hz drift from a cold start. That is within the K2 spec of
100 Hz drift typical from a cold start at 25C (77F). If your ambient
temperature is lower, you can expect more warm-up drift.
Once warmed up, the drift should be small.
Even my stable HP6840 takes about 2 hours
Adam,
The K2 PLL Ref Upgrade manual gives some information on typical drift i.e.
5 to 20 Hz per 15 degrees F on 20 meters. It also explains how changing RA
on the thermistor board can better compensate for the drift. Since your
drift is consistent, I think you should be able to reduce it by
Kevin,
The RA resistor on the thermistor board is intended to compensate for drift
AFTER warmup - such as drift that might occur due to the additional heating
when the KPA100 is transmitting. I do not believe it would be fruitful to
attempt to compensate for the initial warmup drift that one may
: Sunday, December 24, 2006 2:26 PM
To: Kevin Schmidt; elecraft@mailman.qth.net
Subject: RE: [Elecraft] K2 frequency drift
Kevin,
The RA resistor on the thermistor board is intended to compensate for drift
AFTER warmup - such as drift that might occur due to the additional heating
when the KPA100
Don,
I agree about warm up drift. Perhaps I misunderstood Adam, but I
thought that his problem was that even during normal usage he found
objectionable drift when he operated his KPA100 for a while. I presume,
perhaps wrongly, that this is most likely coming from the PLL since I
thought that the
On Sunday 24 December 2006 15:26, Don Wilhelm wrote:
Kevin,
The RA resistor on the thermistor board is intended to compensate for drift
AFTER warmup
In 1978 I bought an Eddystone EA12 from Tom, G3YTO,
sadly SK in 1985. It used to keep my bedroom/shack
warm - thermal stability, and the glow
The K2 drift mentioned by Adam is about 5 ppm for 10 MHz WWV. This isn't
bad for a non-TCXO oscillator. With TCXO oscillators, you can probably get
down to 1 ppm, but it might cost you $50 extra. You can do even better by
mounting the oscillator in an oven (OCXO), but it will cost you a
Dave,
It is not abnormal for electronic equipment to have some warm-up drift, the
K2 is no excpetion, so I would hesitate to call the situation you describe
as a 'problem'.
You can download the K2 Temperature-Compensated PLL Reference Upgrade
document from the Elecraft website - it contains a
Dave;
I designed the K2 VFO stability mod that is now included in all K2's.
Variations in the crystal stability cause each K2 to drift slightly
differently. That's why I included the instructions on how to adjust the
resistor values to minimize the K2's drift.
I tested my K2 from 15C to 45C
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