[Elecraft] Sidetone questions -- copy speed vs sidetone pitch

[Sverre Holm]

> -----Original Message-----
> 
> My question concerns what pitch is easier to copy 
> when receiving fast cw when no qrm is present.   

There has been research on the topic of sidetone and level. It concluded
with 500 Hz and in some cases even lower tones to be favorable in noise free
environments.  This was published in Scandinavian Audiology, 1992, volume
pages 255-60:

Recognition of telegraphy signs at different listening levels and
frequencies.

by Montnemery P, Almqvist B, Harris S., Department of Audiology, University
Hospital, Lund, Sweden.

"The recognition of telegraphy masked by noise at 40 and 80 signs/min
telegraphy speed was studied in 10 normal-hearing subjects at different
sound pressure levels (25-85 dB SPL in steps of 5 dB) as well as at
different test frequencies (2000, 1000, 800, 630, 500 and 250 Hz). The
ability to recognize the signs varied with varying SPL. Recognition for most
of the subjects was best at an SPL close to 70 dB. All subjects improved
their recognition as the frequency was lowered to 500 Hz, some even at 250
Hz. These facts should be taken into consideration when training telegraphy
operators as well as in the construction of radio receivers to permit
listening at low frequencies. Furthermore, the critical ratio was calculated
at the different test frequencies."

40 and 80 signs/minute should be 8 and 16 wpm. Peter Montnemery is SM7CMY
and a K2 owner, but I am not sure that he is active on this list any longer.


73

Sverre
LA3ZA
http://www.qslnet.de/la3za/