date:20240122

Re: [wsjt-devel] Q65-15A Broken?

2024-01-22 Thread Joe Taylor via wsjt-devel


Hi Dwayne,

I discussed these issues at some length with Bob, KA1GT, some 1.5 years 
ago.  Here are the relevant details.


Sure, we could make a version of Q65-15A that can decode after normal 
EME delays.  It would not be a very good fit for the channel, however.


This is because the duration of a Q65 transmission is 12.8 s, and the 
transmission starts at t = 0.5 s into the 15-second sequence.  Add a 2.7 
s EME delay, and you're already 1 second into the next sequence -- even 
without any clock errors.


You could make the Tx duration smaller, say 10 s.  Then, if the 
transmission starts at t=0.5 s and there's a 2.7 s EME delay, reception 
would be complete at t=10.5 + 2.7 = 13.2 s, and (if clocks were spot on) 
the decoder would have 1.8 s to do its thing.  Even this is not really 
enough, because clocks are not always "spot on".  Moreover, you would 
lose an additional 10*log(12.8/10.0) = 1 dB of sensitivity.  WSJT moders 
do a lot to gain every 0.1 dB of sensitivity, so we certainly don't want 
to to that!


Fifteen-second sequences are not an efficient choice for a path with 
delays as large as 2.7 s.  If there were many times more EME activity 
than at present, so that very fast QSOs were desirable in contests, and 
if nearly everybody had many dB's to spare on the EME path, something 
like Q65-15A might be desirable.  As things stand, our advice is to use 
Q65-30B for EME on 1296 MHz.


-- 73, Joe, K1JT

On 1/22/2024 3:36 PM, Dwayne Sinclair wrote:

Thanks Joe for QSO and the confirmation that Q65-15A is not to be used for EME. 
Our “bad” in that in our circles we may have been referring to it as broken.

The attached article details some of the testing that has occurred to date in 
an attempt to work with what we have.

I guess the EME community (including me) are looking for a faster QSO where 
conditions and equipment support it?

Regards Dwayne AB6A


On Jan 22, 2024, at 11:54 AM, Joe Taylor  wrote:

Hi Dwayne,

Thanks for the QSO with W2ZQ, last evening.

Who is saying Q65-15A is broken, and why?

Are you (or they?) talking about EME?  If so, are you aware that the Q65-15x 
submodes are not supposed to work for EME.  The 2.5 s EME delay is too large.

-- 73, Joe, K1JT


On 1/22/2024 2:04 PM, Dwayne Sinclair via wsjt-devel wrote:
There have been ongoing reports from various operators best summarized in the 
post attached that Q65-15A is “broken”. What is current consensus on this and 
if it is broken, is there any plans to address the issues?
Q65-15A Part II Testing and Sensitivity Bob Atkins - KA1GT 

bobatkins.com 
favicon.ico 

Regards Dwayne AB6A
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Re: [wsjt-devel] Q65-15A Broken?

2024-01-22 Thread Dwayne Sinclair via wsjt-devel

Thanks Joe for sharing. 1296Mhz and above is technically pretty easy to do with 
modest stations and not that much power especially when one end is doing the 
heavy lifting with a larger dish. I would say that many of my current QSO’s do 
have spare dB’s where even Phone would be possible. In routine operation we 
move from 23CM EME Q65-60C to 120D and up from 60C to 30B when conditions and 
equipment support it. 

Speaking for myself and as a wish list item, a mode faster than 30B would be 
desirable for both Contests and Equipment since 30B and 60C is pretty hard on 
Amps - 120D for some Amps is impossible. Maybe 20 seconds is a compromise but 
there would be some complexity around 3 cycles a minute.

Anyhow - Wishlist for now.

Thanks,
Dwayne AB6A

> On Jan 22, 2024, at 1:04 PM, Joe Taylor  wrote:
> 
> Hi Dwayne,
> 
> I discussed these issues at some length with Bob, KA1GT, some 1.5 years ago.  
> Here are the relevant details.
> 
> Sure, we could make a version of Q65-15A that can decode after normal EME 
> delays.  It would not be a very good fit for the channel, however.
> 
> This is because the duration of a Q65 transmission is 12.8 s, and the 
> transmission starts at t = 0.5 s into the 15-second sequence.  Add a 2.7 s 
> EME delay, and you're already 1 second into the next sequence -- even without 
> any clock errors.
> 
> You could make the Tx duration smaller, say 10 s.  Then, if the transmission 
> starts at t=0.5 s and there's a 2.7 s EME delay, reception would be complete 
> at t=10.5 + 2.7 = 13.2 s, and (if clocks were spot on) the decoder would have 
> 1.8 s to do its thing.  Even this is not really enough, because clocks are 
> not always "spot on".  Moreover, you would lose an additional 
> 10*log(12.8/10.0) = 1 dB of sensitivity.  WSJT moders do a lot to gain every 
> 0.1 dB of sensitivity, so we certainly don't want to to that!
> 
> Fifteen-second sequences are not an efficient choice for a path with delays 
> as large as 2.7 s.  If there were many times more EME activity than at 
> present, so that very fast QSOs were desirable in contests, and if nearly 
> everybody had many dB's to spare on the EME path, something like Q65-15A 
> might be desirable.  As things stand, our advice is to use Q65-30B for EME on 
> 1296 MHz.
> 
>   -- 73, Joe, K1JT
> 
> On 1/22/2024 3:36 PM, Dwayne Sinclair wrote:
>> Thanks Joe for QSO and the confirmation that Q65-15A is not to be used for 
>> EME. Our “bad” in that in our circles we may have been referring to it as 
>> broken.
>> The attached article details some of the testing that has occurred to date 
>> in an attempt to work with what we have.
>> I guess the EME community (including me) are looking for a faster QSO where 
>> conditions and equipment support it?
>> Regards Dwayne AB6A
>>> On Jan 22, 2024, at 11:54 AM, Joe Taylor  wrote:
>>> 
>>> Hi Dwayne,
>>> 
>>> Thanks for the QSO with W2ZQ, last evening.
>>> 
>>> Who is saying Q65-15A is broken, and why?
>>> 
>>> Are you (or they?) talking about EME?  If so, are you aware that the 
>>> Q65-15x submodes are not supposed to work for EME.  The 2.5 s EME delay is 
>>> too large.
>>> 
>>>-- 73, Joe, K1JT
>>> 
 On 1/22/2024 2:04 PM, Dwayne Sinclair via wsjt-devel wrote:
 There have been ongoing reports from various operators best summarized in 
 the post attached that Q65-15A is “broken”. What is current consensus on 
 this and if it is broken, is there any plans to address the issues?
 Q65-15A Part II Testing and Sensitivity Bob Atkins - KA1GT 
 
 bobatkins.com 
favicon.ico 
 
 Regards Dwayne AB6A
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 wsjt-devel@lists.sourceforge.net
 https://lists.sourceforge.net/lists/listinfo/wsjt-devel



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Re: [wsjt-devel] Q65-15A Broken?

2024-01-22 Thread Joe Taylor via wsjt-devel


Hi Dwayne,

Thanks for the QSO with W2ZQ, last evening.

Who is saying Q65-15A is broken, and why?  Are you (or they?) talking 
about EME?  If so, are you aware that the Q65-15x submodes are not 
supposed to work for EME.  The 2.5 s EME delay is too large.


-- 73, Joe, K1JT

On 1/22/2024 2:04 PM, Dwayne Sinclair via wsjt-devel wrote:
There have been ongoing reports from various operators best summarized 
in the post attached that Q65-15A is “broken”. What is current consensus 
on this and if it is broken, is there any plans to address the issues?


Q65-15A Part II Testing and Sensitivity Bob Atkins - KA1GT 


bobatkins.com 
favicon.ico 



Regards Dwayne AB6A


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Re: [wsjt-devel] Q65-15A Broken?

2024-01-22 Thread Dwayne Sinclair via wsjt-devel

Yes - many of us are already using Q65-30B on 23CM EME. Looking for “faster” ;)

Regards Dwayne AB6A

> On Jan 22, 2024, at 12:44 PM, Lance Collister, W7GJ via wsjt-devel 
>  wrote:
> 
> There is the 30 second option...
> 
> On 1/22/2024 20:36:37, Dwayne Sinclair via wsjt-devel wrote:
>> Thanks Joe for QSO and the confirmation that Q65-15A is not to be used for 
>> EME. Our “bad” in that in our circles we may have been referring to it as 
>> broken.
>> 
>> The attached article details some of the testing that has occurred to date 
>> in an attempt to work with what we have.
>> 
>> I guess the EME community (including me) are looking for a faster QSO where 
>> conditions and equipment support it?
>> 
>> Regards Dwayne AB6A
>> 
>>> On Jan 22, 2024, at 11:54 AM, Joe Taylor  wrote:
>>> 
>>> Hi Dwayne,
>>> 
>>> Thanks for the QSO with W2ZQ, last evening.
>>> 
>>> Who is saying Q65-15A is broken, and why?
>>> 
>>> Are you (or they?) talking about EME?  If so, are you aware that the 
>>> Q65-15x submodes are not supposed to work for EME.  The 2.5 s EME delay is 
>>> too large.
>>> 
>>>-- 73, Joe, K1JT
>>> 
 On 1/22/2024 2:04 PM, Dwayne Sinclair via wsjt-devel wrote:
 There have been ongoing reports from various operators best summarized in 
 the post attached that Q65-15A is “broken”. What is current consensus on 
 this and if it is broken, is there any plans to address the issues?
 Q65-15A Part II Testing and Sensitivity Bob Atkins - KA1GT 
 
 bobatkins.com 
favicon.ico 
 
 Regards Dwayne AB6A
 ___
 wsjt-devel mailing list
 wsjt-devel@lists.sourceforge.net
 https://lists.sourceforge.net/lists/listinfo/wsjt-devel
>> 
>> ___
>> wsjt-devel mailing list
>> wsjt-devel@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/wsjt-devel
> 
> -- 
> Lance Collister, W7GJ(ex WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8, E51SIX, 
> 3D2LR, 5W0GJ, E6M, TX5K, KH8/W7GJ, V6M, T8GJ, VK9CGJ, VK9XGJ, C21GJ, CP1GJ, 
> S79GJ, TX7MB, TO7GJ, 3B9GJ)
> P.O. Box 73
> Frenchtown, MT   59834-0073
> USA
> TEL: (406) 626-5728
> QTH: DN27ub
> URL: http://www.bigskyspaces.com/w7gj
> Skype: lanceW7GJ
> 2m DXCC #11 - 6m DXCC #815 - FFMA #7
> 
> Interested in 6m EME?  Ask me about subscribing to the new Magic Band EME
> email group, or just fill in the request box at the bottom of my web
> page (above)!
> 
> 
> 
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Re: [wsjt-devel] Q65-15A Broken?

2024-01-22 Thread Lance Collister, W7GJ via wsjt-devel


There is the 30 second option...

On 1/22/2024 20:36:37, Dwayne Sinclair via wsjt-devel wrote:

Thanks Joe for QSO and the confirmation that Q65-15A is not to be used for EME. 
Our “bad” in that in our circles we may have been referring to it as broken.

The attached article details some of the testing that has occurred to date in 
an attempt to work with what we have.

I guess the EME community (including me) are looking for a faster QSO where 
conditions and equipment support it?

Regards Dwayne AB6A


On Jan 22, 2024, at 11:54 AM, Joe Taylor  wrote:

Hi Dwayne,

Thanks for the QSO with W2ZQ, last evening.

Who is saying Q65-15A is broken, and why?

Are you (or they?) talking about EME?  If so, are you aware that the Q65-15x 
submodes are not supposed to work for EME.  The 2.5 s EME delay is too large.

-- 73, Joe, K1JT


On 1/22/2024 2:04 PM, Dwayne Sinclair via wsjt-devel wrote:
There have been ongoing reports from various operators best summarized in the 
post attached that Q65-15A is “broken”. What is current consensus on this and 
if it is broken, is there any plans to address the issues?
Q65-15A Part II Testing and Sensitivity Bob Atkins - KA1GT 

bobatkins.com 
favicon.ico 

Regards Dwayne AB6A
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--
Lance Collister, W7GJ(ex WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8, E51SIX, 3D2LR, 
5W0GJ, E6M, TX5K, KH8/W7GJ, V6M, T8GJ, VK9CGJ, VK9XGJ, C21GJ, CP1GJ, S79GJ, 
TX7MB, TO7GJ, 3B9GJ)
P.O. Box 73
Frenchtown, MT   59834-0073
USA
TEL: (406) 626-5728
QTH: DN27ub
URL: http://www.bigskyspaces.com/w7gj
Skype: lanceW7GJ
2m DXCC #11 - 6m DXCC #815 - FFMA #7

Interested in 6m EME?  Ask me about subscribing to the new Magic Band EME
email group, or just fill in the request box at the bottom of my web
page (above)!



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Re: [wsjt-devel] Q65-15A Broken?

2024-01-22 Thread Dwayne Sinclair via wsjt-devel

Thanks Joe for QSO and the confirmation that Q65-15A is not to be used for EME. 
Our “bad” in that in our circles we may have been referring to it as broken.

The attached article details some of the testing that has occurred to date in 
an attempt to work with what we have.

I guess the EME community (including me) are looking for a faster QSO where 
conditions and equipment support it? 

Regards Dwayne AB6A

> On Jan 22, 2024, at 11:54 AM, Joe Taylor  wrote:
> 
> Hi Dwayne,
> 
> Thanks for the QSO with W2ZQ, last evening.
> 
> Who is saying Q65-15A is broken, and why?
> 
> Are you (or they?) talking about EME?  If so, are you aware that the Q65-15x 
> submodes are not supposed to work for EME.  The 2.5 s EME delay is too large.
> 
>-- 73, Joe, K1JT
> 
>> On 1/22/2024 2:04 PM, Dwayne Sinclair via wsjt-devel wrote:
>> There have been ongoing reports from various operators best summarized in 
>> the post attached that Q65-15A is “broken”. What is current consensus on 
>> this and if it is broken, is there any plans to address the issues?
>> Q65-15A Part II Testing and Sensitivity Bob Atkins - KA1GT 
>> 
>> bobatkins.com 
>>favicon.ico 
>> 
>> Regards Dwayne AB6A
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Re: [wsjt-devel] Q65-15A Broken?

2024-01-22 Thread Joe Taylor via wsjt-devel


Hi Dwayne,

Thanks for the QSO with W2ZQ, last evening.

Who is saying Q65-15A is broken, and why?

Are you (or they?) talking about EME?  If so, are you aware that the 
Q65-15x submodes are not supposed to work for EME.  The 2.5 s EME delay 
is too large.


-- 73, Joe, K1JT

On 1/22/2024 2:04 PM, Dwayne Sinclair via wsjt-devel wrote:
There have been ongoing reports from various operators best summarized 
in the post attached that Q65-15A is “broken”. What is current consensus 
on this and if it is broken, is there any plans to address the issues?


Q65-15A Part II Testing and Sensitivity Bob Atkins - KA1GT 


bobatkins.com 
favicon.ico 



Regards Dwayne AB6A


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[wsjt-devel] Q65-15A Broken?

2024-01-22 Thread Dwayne Sinclair via wsjt-devel

There have been ongoing reports from various operators best summarized in the 
post attached that Q65-15A is “broken”. What is current consensus on this and 
if it is broken, is there any plans to address the issues? 

https://www.bobatkins.com/radio/Q65-15_eme_II.html

Regards Dwayne AB6A___
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Re: [wsjt-devel] Q65-15A Broken?

Re: [wsjt-devel] Q65-15A Broken?

Re: [wsjt-devel] Q65-15A Broken?

Re: [wsjt-devel] Q65-15A Broken?

Re: [wsjt-devel] Q65-15A Broken?

Re: [wsjt-devel] Q65-15A Broken?

Re: [wsjt-devel] Q65-15A Broken?

[wsjt-devel] Q65-15A Broken?

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