[Fourlanders] Fw: Re: [wsjtgroup] Re: MSK 144 question

Sun Feb 11 18:24:15 EST 2018

That is fine. We just need to establish the numbers accurately.

On Sun, Feb 11, 2018, 5:17 PM John Kludt <johnnykludt at earthlink.net> wrote:

> Bill,
>
> Probably cannot adjust at the hardware level but the software allows for
> correction factors to be put in place.
>
> Johnny
>
> -----Original Message-----
> From: Bill Pence
> Sent: Feb 11, 2018 5:09 PM
> To: John Kludt
> Cc: Fourlanders
> Subject: Re: [Fourlanders] Fw: Re: [wsjtgroup] Re: MSK 144 question
>
> Thinking about this and some of our setups makes me wonder about either
> characterizing or calibrating our stations.
>
> Wd neef to plan a tine and method to get sn ultrastable frequency standard
> snd measure the accuracy of the stations and transverters for our setup.
>
> Not sure we can adjust, but we need to know our freq error so we fan make
> adjustments
>
>
>
> On Sun, Feb 11, 2018, 4:59 PM John Kludt <johnnykludt at earthlink.net>
> wrote:
>
>> Guys,
>>
>> Interesting stuff and new things to learn and work with.  With our older
>> rigs, what do we know about frequency accuracy.  Remember "wide open" we
>> are looking at a frequency tolerance of 200 Hz.
>>
>> With the slow modes FT8, JT65, time is key.  With the fast modes like
>> MSK144 frequency is key.
>>
>> Johnny
>>
>> -----Forwarded Message-----
>> From: "Bob McGraw K4TAX RMcGraw at Blomand.net [wsjtgroup]"
>> Sent: Feb 10, 2018 9:44 AM
>> To: Joe Dzekevich , wsjtgroup at yahoogroups.com
>> Subject: Re: [wsjtgroup] Re: MSK 144 question
>>
>>
>>
>> Joe makes very good points.   Additionally this clearly confirms that
>> improved frequency accuracy is a must for many modes.  While Joe attained
>> good accuracy using 20 MHz WWV, one must ask, what about other bands?
>> i.e. 160M? or others?  I find the frequency variation will likely not be
>> the same for all bands.   Some may be a bit low while others may be a bit
>> high.  This has to do with the accuracy of the various oscillators, the
>> accuracy of the reference oscillator and the math in the operating system.
>>
>> Before settling on one value, one should check several bands using
>> several time/frequency broadcast and normalize the overall error.    With
>> this, I find my K3S, after warm-up and reference oscillator adjustments, to
>> be +/- 1 Hz or better, all bands 160M - 6M.  As to 2M, using my DownEast
>> Microwave transverter, I must add correction for the TCXO error in that
>> unit.
>>
>> 73
>>
>> Bob, K4TAX
>>
>> On 2/10/2018 6:31 AM, Joe Dzekevich wrote:
>>
>> As a follow-up to Bob’s note on freq cal mode.....I have two rigs: a 3
>> year old TS-590SG and a 13 year old IC-746PRO.  I ran the freq cal test on
>> both, and the TS-590SG had warm-up freq drift issues and the IC-746PRO also
>> had the drift issues.  So, given that MSK144 needs to have frequency
>> accuracy within 200 Hz, I dropped-in TCXO’s into each rig.  A cheap
>> TS-590SG TCXO got me within 4 Hz on WWV 20 MHz and I was able to adjust the
>> IC-746PRO to within 1 Hz on WWV 20 Mhz.  Both rigs were also now stable as
>> a rock.
>>
>>
>>
>> But....that does not mean that when you get up to 6M and 2M that you have
>> the same frequency accuracy tolerance.  Using a 200 Mhz counter, I could
>> see that while things on 6M were very good on both rigs, when the IC-746PRO
>> got up to 2M, it was further off frequency than I wanted.  It was within
>> the 200 Hz, but barely, meaning that if stations on MSK144 were off in the
>> other direction, I would not decode them.  To fix that, in the WSJT-X
>> frequency tables, lower part, you can put-in a frequency offset, plus or
>> minus, in Hz, for each band.  For 6M I put-in a very slight offset and on
>> 2M I put-in a slightly larger offset.  The goal was to get the rigs within
>> +/- 25 Hz so I could decode other stations should their offset be in the
>> opposite direction as mine and be well within the 200 Hz for deep decoding.
>>
>>
>>
>> In short – everything was a success.  Basically with modes like FT8 you
>> need very accurate time.  With the fast modes like MSK144 for meteor
>> scatter, you need very accurate frequency.
>>
>>
>>
>> Joe, K1YOW
>>
>>
>>
>>
>> ------------------------------
>>
>> *From:* wsjtgroup at yahoogroups.com [mailto:wsjtgroup at yahoogroups.com
>> <wsjtgroup at yahoogroups.com>] *On Behalf Of *Bob McGraw K4TAX
>> RMcGraw at Blomand.net [wsjtgroup]
>> *Sent:* Friday, February 09, 2018 8:04 PM
>> *To:* wsjtgroup at yahoogroups.com
>> *Subject:* [wsjtgroup] Re: MSK 144 question
>>
>>
>>
>>
>>
>> Joe made reference to the radio master oscillator accuracy which is
>> where the display numbers on the radio originate.
>>
>> To that end, the latest release of WSJT-X has a nice mode being
>> FreqCal.   If you have your radio and computer configured for CAT control,
>> selecting this mode will step the receiver through various frequency
>> standard broadcasts.  Or you can manually select the frequencies of your
>> choice.
>>
>> The software automatically sets the radio via CAT control to the
>> specific frequency, and then inserts a - 1500 Hz offset.   The table will
>> show as such as below. The column of values DF is the error in Hz..   From
>> this table I presume my radio to be about -0.2 to -0.5 Hz low looking at
>> the DF column.
>>
>>  UTC       Freq Cal Offset  Fmeas      DF    Level   S/N
>>
>> 00:42:39 2500 1 1500 1499.797 -0.203 -4.6 47.8
>>
>> 00:42:41 2500 1 1500 1499.700 -0.300 -4.2 45.8
>>
>> 00:42:43 2500 1 1500 1499.644 -0.356 -6.2 47.9
>>
>> 00:42:49 2500 1 1500 1499.747 -0.253 -4.8 50.6
>>
>> 00:42:51 2500 1 1500 1499.661 -0.339 -0.7 45.4
>>
>> 00:42:54 2500 1 1500 1499.685 -0.315 -2.0 46.7
>>
>> 00:42:56 2500 1 1500 1499.745 -0.255 -2.0 47.0
>>
>> 00:42:58 2500 1 1500 1499.775 -0.225 -1.3 46.6
>>
>> 00:43:04 2500 1 1500 1499.497 -0.503 -3.9 49.2
>>
>> 00:43:06 2500 1 1500 1499.506 -0.494 -4.4 49.9
>>
>> 00:43:09 2500 1 1500 1499.551 -0.449 -2.9 48.5
>>
>> 00:43:11 2500 1 1500 1499.618 -0.382 -2.0 47.2
>>
>> 00:43:13 2500 1 1500 1499.655 -0.345 -2.6 47.5
>>
>> 00:43:19 2500 1 1500 1499.744 -0.256 -3.4 48.9
>>
>>
>>
>> This has proven to be a good check regarding ones radio.  I've use a high
>> precision source to verify the results are quite accurate.  Again this says
>> to me the digital readout on your radio may or may not be as accurate as
>> you might like to think and believe.    In my case I've adjusted the
>> reference oscillator in my radio to produce the least error on all
>> frequencies checked between 2.5 MHz,  5.0 MHz, 10 MHz, 15 MHz and 25 MHz
>> WWV signals.
>>
>>
>>
>> 73
>>
>> Bob, K4TAX
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> Re: MSK 144 question
>> <https://groups.yahoo.com/neo/groups/wsjtgroup/conversations/topics/27882;_ylc=X3oDMTJyNGk4dnBtBF9TAzk3MzU5NzE1BGdycElkAzU3NjQyNTQEZ3Jwc3BJZAMxNzA1MDYzMTA4BG1zZ0lkAzI3ODgyBHNlYwNkbXNnBHNsawN2bXNnBHN0aW1lAzE1MTgyMTI0NDU->
>> *Fri Feb 9, 2018 6:31 am (PST) . Posted by: * *"Joe Dzekevich"
>> jdzekevich <joedzekevich at charter.net?subject=Re%3A%20MSK%20144%20question>*
>>
>>
>>
>> Yes, the MSK144 Tx freq is 1500. Now, what you are seeing are folks being
>> off freq depending on the accuracy of their rig's freq osc. Most folks
>> running MSK144 meteor scatter are usually within +/- 25 Hz or so. If you
>> set your freq tol to 200 and deep decode, provided your CPU and memory can
>> handle that, you should decode folks on 50.260 with the 1500 Hz offset.
>>
>> Then, add-in other frequencies to your table, like 50.255, 265, whatever.
>> That way you can do easy QSY's or call CQ on .260 and QSY to 255 or
>> whatever
>> if crowded.
>>
>> Basically, if your F Tol is 200, then you will decode stations that are
>> within 200 Hz of the 1500.
>>
>> Joe, K1YOW
>>
>>
>> __._,_.___
>> ------------------------------
>> Posted by: Bob McGraw K4TAX <rmcgraw at blomand.net>
>> ------------------------------
>> Reply via web post
>> <https://groups.yahoo.com/neo/groups/wsjtgroup/conversations/messages/27900;_ylc=X3oDMTJxcTE0cGVpBF9TAzk3MzU5NzE0BGdycElkAzU3NjQyNTQEZ3Jwc3BJZAMxNzA1MDYzMTA4BG1zZ0lkAzI3OTAwBHNlYwNmdHIEc2xrA3JwbHkEc3RpbWUDMTUxODI3Mzg3NQ--?act=reply&messageNum=27900>
>> • Reply to sender
>> <rmcgraw at blomand.net?subject=Re%3A%20%5Bwsjtgroup%5D%20Re%3A%20MSK%20144%20question>
>> • Reply to group
>> <wsjtgroup at yahoogroups.com?subject=Re%3A%20%5Bwsjtgroup%5D%20Re%3A%20MSK%20144%20question>
>> • Start a New Topic
>> <https://groups.yahoo.com/neo/groups/wsjtgroup/conversations/newtopic;_ylc=X3oDMTJldWMxaTVvBF9TAzk3MzU5NzE0BGdycElkAzU3NjQyNTQEZ3Jwc3BJZAMxNzA1MDYzMTA4BHNlYwNmdHIEc2xrA250cGMEc3RpbWUDMTUxODI3Mzg3NQ-->
>> • Messages in this topic
>> <https://groups.yahoo.com/neo/groups/wsjtgroup/conversations/topics/27880;_ylc=X3oDMTM2OXBiOG5jBF9TAzk3MzU5NzE0BGdycElkAzU3NjQyNTQEZ3Jwc3BJZAMxNzA1MDYzMTA4BG1zZ0lkAzI3OTAwBHNlYwNmdHIEc2xrA3Z0cGMEc3RpbWUDMTUxODI3Mzg3NQR0cGNJZAMyNzg4MA-->
>> (5)
>> ------------------------------
>> Have you tried the highest rated email app? <https://yho.com/1wwmgg>
>> With 4.5 stars in iTunes, the Yahoo Mail app is the highest rated email
>> app on the market. What are you waiting for? Now you can access all your
>> inboxes (Gmail, Outlook, AOL and more) in one place. Never delete an email
>> again with 1000GB of free cloud storage.
>> ------------------------------
>> To unsubscribe, send an email to:
>> wsjtgroup-unsubscribe at yahoogroups.com
>> Visit Your Group
>> <https://groups.yahoo.com/neo/groups/wsjtgroup/info;_ylc=X3oDMTJlaTlpOXRzBF9TAzk3MzU5NzE0BGdycElkAzU3NjQyNTQEZ3Jwc3BJZAMxNzA1MDYzMTA4BHNlYwN2dGwEc2xrA3ZnaHAEc3RpbWUDMTUxODI3Mzg3NQ-->
>>
>>    - New Members
>>    <https://groups.yahoo.com/neo/groups/wsjtgroup/members/all;_ylc=X3oDMTJmcnAyZWVkBF9TAzk3MzU5NzE0BGdycElkAzU3NjQyNTQEZ3Jwc3BJZAMxNzA1MDYzMTA4BHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzE1MTgyNzM4NzU->
>>    14
>>
>> [image: Yahoo! Groups]
>> <https://groups.yahoo.com/neo;_ylc=X3oDMTJkcW1vcWY2BF9TAzk3NDc2NTkwBGdycElkAzU3NjQyNTQEZ3Jwc3BJZAMxNzA1MDYzMTA4BHNlYwNmdHIEc2xrA2dmcARzdGltZQMxNTE4MjczODc3>
>> • Privacy <https://info.yahoo.com/privacy/us/yahoo/groups/details.html>
>> • Unsubscribe <wsjtgroup-unsubscribe at yahoogroups.com?subject=Unsubscribe>
>> • Terms of Use <https://info.yahoo.com/legal/us/yahoo/utos/terms/>
>>
>> .
>>
>> __,_._,___
>>
>> _______________________________________________
>> Fourlanders mailing list
>> Fourlanders at contesting.com
>> http://lists.contesting.com/mailman/listinfo/fourlanders
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.contesting.com/pipermail/fourlanders/attachments/20180211/a37cf02d/attachment-0001.html>