[RTTY] Fun, but

[Joe Subich, W4TV]

> No, that transmit bandpass filter had only addressed the 
> symptom, not the cause, Joe.  As a result, as a few people 
> have reported after installing the Feb 9 Beta firmware, 
> certain settings still caused the envelope glitches.

It addressed some but not all of the causes.  The current 
alpha - which I do have - seems to have addressed the root 
cause.  However, the bandpass filter may still be of value 
for some of the lousy AFSK generators out there. 

> Until this is sent to a wider beta audience, we don't know 
> yet if it fixes all cases.  And even so, there are going to 
> be a whole lots of people who will still be transmitting 
> dirty RTTY signals.  

There are a whole lot of dirty RTTY signals out there not 
generated by a particular brand of radio.  Many users in 
general need to understand the issues of overdriving mic 
inputs, operating system sounds, hum, etc.  There are more 
of those problems out there than the AFSK "glitch" in one 
DSP implementation.  

> Please stop blaming other peoples' receivers, when in this 
> case the transmitter is at fault.  I am sure Tom's receiver 
> is fine, especially where his QTH is.  

Yes, every operator has a responsibility to be sure that his 
signal is clean.  However, no user has the expectation of any 
form of "guard band" around his operating frequency.  Whether 
it applies to Tom or not, there are too many operators with 
2.7 KHz filters and click on the waterfall software who expect 
to be protected from AGC desense within 5 KHz.  

73, 

   ... Joe, W4TV 
 




> -----Original Message-----
> From: Kok Chen [mailto:chen at mac.com] 
> Sent: Sunday, March 01, 2009 3:33 PM
> To: RTTY Reflector
> Cc: Joe Subich, W4TV
> Subject: Re: [RTTY] Fun, but
> 
> 
> 
> On Mar 1, 2009, at 11:32 AM, Joe Subich, W4TV wrote:
> 
> > The issue is with AFSK not FSK.  The first fix was released in the 
> > pubic beta software (MCU 2.82/DSP 2.00) dated 9 Feb 2009 
> and includes 
> > a transmit BPF (CONFIG:AFSK TX).
> 
> 
> No, that transmit bandpass filter had only addressed the 
> symptom, not  
> the cause, Joe.  As a result, as a few people have reported after  
> installing the Feb 9 Beta firmware, certain settings still 
> caused the  
> envelope glitches.
> 
> Take a careful look at the early notes that came with the Alpha  
> firmware (the latest alpha came out on February 26) which Wayne had  
> sent as email to a couple of people (you and I included).
> 
> One alpha tester whose problem the Feb 9 Beta did not cure, has  
> reported that the latest Alpha is no longer producing audible  
> keyclicks.  So, there is hope that the root cause, and not the  
> symptom, is finally addressed.  This why I used "[[ currently ]]" in  
> my earlier posting, and specially placed emphasis on the word.
> 
> Until this is sent to a wider beta audience, we don't know yet if it  
> fixes all cases.  And even so, there are going to be a whole lots of  
> people who will still be transmitting dirty RTTY signals.
> 
> > Of course none if this makes any difference if your old 
> receiver folds 
> > when another station moves in 100 Hz away.
> 
> There you go again, Joe, another red herring.
> 
> Please stop blaming other peoples' receivers, when in this case the  
> transmitter is at fault.  I am sure Tom's receiver is fine, 
> especially  
> where his QTH is.  He has been doing RTTY for long enough to 
> identify  
> an overly broad signal from an overloaded front end.
> 
> We are addressing overly broad RTTY signals here, not loud RTTY  
> signals.  You cannot prevent your transmitted signal from being loud  
> to another ham.  But you can avoid being unnecessarily broad.
> 
> 73
> Chen, W7AY
>