Calibrating the Oscillator and Other Start-Up Questions for K3

[KC2VNI]

All: I am happy to report that S/N 3823 now has been powered up. I am following the following calibration steps on pages 65-66 of the assembly manual for the low power (5W) configuration. My personal computer is not working so I cannot connect the radio to a lap-top. I am doing all of the calibration and set up by the radio and whatever firmware has been shipped loaded in the radio.

Here are some questions:

1) I put the factory filter 2.7kHZ with offset of -0.82 in slot 3 and I do not have any other filters installed at this time. I put the filter there in case I want to add other filters later on. I set up the filter for bandwidth of 2.7 assuming that 2.7 is given in units KHZ. Is this correct? Also, I turned everything else for filters 1,2,4, and 5 off. Let me know if there's something I'm missing. Some additional questions:

a) I set the receive filter enables to filter 3 in my case for all modes USB, LSB, CW, etc.

b) What filter loss compensation should be used

c) I set the transmit filter selection to filter 3


2) Testing output with dummy load for transmitter gain: I used an MFJ load and tied it to antenna input 1. I believe that I performed the test per the instructions but the load did not feel very warm at 5W. Is this normal?

3) Reference Osillator Calibration: This seems to be the tricky 1. I have the standard 5PPM oscillator. I do not have a frequency counter. So this leaves me with Method 2 on page 50 of the operations manual. Now, in order to zero-beat this, I would assume that I need to attach my antenna to the radio. Here are questions:

a) Is my assumption correct about attaching the antenna to the radio?

b) What other parameters need to be adjusted (and what would good suggested values be) BEFORE I attach the antenna to the radio? I am not only referring to "set-up" parameters but other items that would interfere with my operating the radio.

c) Should I place the K3 antenna tuner on when performing an oscillator calibration? I would assume so to make the antenna match the transceiver

d) What should I use as a "strong broadcast station" at 10,15,or 20MHz? Does anybody have a suggested frequency I should use? Would one of the signal beacons used for propagation studies be a good referece? For what it's worth, I am in the Southern NJ area and all I have been using is my local repeater on 2M so I have NO idea as to what is or what is not a good frequency to use.

e) Would I be better off purchasing the XG2 mini project in lieu of trying to do oscillator calibration form a strong broadcast station for a reference oscillator? OR would I be better off shipping the radio back to Elecraft and having them do an oscillator calibration in the factory?

f) I had purchased the 100W power amp. It looks like I have to perform the transmitter gain calibraiton again and there is a calibration of a temperature sensor as well. Does the temperature sensor unit require calibration equipment on my part? Do I have to use the latest firmware from the website to make this work?

I realize I've asked alot of questions here. Any help would be appreciated.

73,

Steve de KC2VNI


 

[Julian, G4ILO]

I can't answer all of those. As for the frequency calibration there are many ways to do that, and it probably isn't all that important anyway unless you are doing some specialist operating that requires you to know your frequency to within a few Hz, as it is unlileky to be all that far out as received from the factory anyway.

Whether you use a broadcast station or a frequency standard like WWV really depends on which you receive strongest. If using a broadcast station then Deutsche Welle is generally regarded as being pretty accurate. If you tune through the SW band in SSB 1KHz off the 5KHz multiples you'll probably notice that most stations give an identical pitched heterodyne, a few don't. Don't use any of the latter.

I use WSPR (one of the modes developed by K1JT) which demands high frequency accuracy and one of the features of the latest WSPR software is a tool that measures an audio frequency, to aid with transceiver calibration. So I use that to measure the frequency of the heterodyne when 1KHz off, and adjust the oscillator calibration value until I get as close as possible to 1000Hz.

[Don Wilhelm-4]

Steve,

See in-line answers below.

73,
Don W3FPR

KC2VNI wrote:

> Here are some questions:
>
> 1) I put the factory filter 2.7kHZ with offset of -0.82 in slot 3 and I do
> not have any other filters installed at this time. I put the filter there in
> case I want to add other filters later on. I set up the filter for bandwidth
> of 2.7 assuming that 2.7 is given in units KHZ. Is this correct? Also, I
> turned everything else for filters 1,2,4, and 5 off. Let me know if there's
> something I'm missing. Some additional questions:
>
> a) I set the receive filter enables to filter 3 in my case for all modes
> USB, LSB, CW, etc.
>
> b) What filter loss compensation should be used
>
> c) I set the transmit filter selection to filter 3
>  

*** You did it correctly ***
> 2) Testing output with dummy load for transmitter gain: I used an MFJ load
> and tied it to antenna input 1. I believe that I performed the test per the
> instructions but the load did not feel very warm at 5W. Is this normal?
>  
*** You did not say which MFJ Dummy Load you used, but it is likely
rated for greater than 100 watts, and it will not get very warm at 5
watts - in fact it may not be noticeable without a precision temperature
probe. ***
> 3) Reference Osillator Calibration: This seems to be the tricky 1. I have
> the standard 5PPM oscillator. I do not have a frequency counter. So this
> leaves me with Method 2 on page 50 of the operations manual. Now, in order
> to zero-beat this, I would assume that I need to attach my antenna to the
> radio. Here are questions:
>
> a) Is my assumption correct about attaching the antenna to the radio?
>  
*** Yes, you need to attach an antenna to the K3 ***
> b) What other parameters need to be adjusted (and what would good suggested
> values be) BEFORE I attach the antenna to the radio? I am not only referring
> to "set-up" parameters but other items that would interfere with my
> operating the radio.
>  
*** This answer should be "none" unless you have some special
requirements.  If you are hearing signals from the radio now, all is OK. ***
> c) Should I place the K3 antenna tuner on when performing an oscillator
> calibration? I would assume so to make the antenna match the transceiver
>  
*** It depends on your antenna.  If you can hear signals with the KAT3
set to BYPASS, then use it that way.  You will have to transmit to make
the KAT3 tune, so try to save that until later ***
> d) What should I use as a "strong broadcast station" at 10,15,or 20MHz? Does
> anybody have a suggested frequency I should use? Would one of the signal
> beacons used for propagation studies be a good referece? For what it's
> worth, I am in the Southern NJ area and all I have been using is my local
> repeater on 2M so I have NO idea as to what is or what is not a good
> frequency to use.
>  
*** If you can, use WWV at 5, 10, 15 MHz or 20 MHz.  You will achieve
greater accuracy at the higher frequencies, but propagation conditions
may not allow you to hear a good signal on 15 or 20 MHz at this time -
10 MHz (sometimes 15 MHz) is usually good on the East Coast.  WWV is a
National Standards station which broadcasts standard frequency and time
information.  Be certain you zero-beat (Match the tone with the K3
sidetone) with the carrier and not one of the transmitted tones.  There
are silent periods when no tone is transmitted, so listen for a while if
you are not familiar with the WWV format. ***  Note: If you have web
access, Google for "WWV format" and you will find information about when
and at what frequency the tones are transmitted.
> e) Would I be better off purchasing the XG2 mini project in lieu of trying
> to do oscillator calibration form a strong broadcast station for a reference
> oscillator? OR would I be better off shipping the radio back to Elecraft and
> having them do an oscillator calibration in the factory?
>  
*** The XG2 is not a frequency standard - it is however an oscillator
with a calibrated output level which is convenient for calibrating the
S-meter. ***
> f) I had purchased the 100W power amp. It looks like I have to perform the
> transmitter gain calibraiton again and there is a calibration of a
> temperature sensor as well. Does the temperature sensor unit require
> calibration equipment on my part? Do I have to use the latest firmware from
> the website to make this work?
>  
*** The firmware that was shipped with your K3 will be fine for all the
calibration steps.  You will likely want to update the firmware to gain
the added functionality of the latest.  Look at the Firmware Release
Notes for the specifics. ***
> I realize I've asked alot of questions here. Any help would be appreciated.
>
> 73,
>
> Steve de KC2VNI
>
>  
>
______________________________________________________________
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