[RTTY] Low Tones

[Joe Subich, W4TV]

Are you using FSK or AFSK?  For AFSK, using high tones (2125/2295) 
places the tones such that any harmonics are eliminated by the 
transmitter IF filter.  With low tones, harmonics caused by over- 
driving the microphone circuits are within the transmit audio 
passband and will be transmitted along with the desired tones. 

Many of the older transceivers were also limited to high tones 
for narrow filters to work on receive. 

73, 

   ... Joe, W4TV 
 


> -----Original Message-----
> From: rtty-bounces at contesting.com 
> [mailto:rtty-bounces at contesting.com] On Behalf Of wb5tuf at earthlink.net
> Sent: Monday, March 01, 2010 2:53 PM
> To: rtty at contesting.com
> Subject: [RTTY] Low Tones
> 
> 
> Other that operator preference, is there any advantage to 
> using high or low tones?
>