[1000mp] FT-1000 with Heil PR-40

[Jim Smith]

Oops.  It has been pointed out to me that I got the filters backwards. 
The 250 Hz was a high pass and the 3400 Hz was a low pass.

73, Jim	VE7FO

Jim Smith wrote:
> Depends what you mean by "normal" SSB purposes.
> 
> Several decades ago I was a designer of telephone carrier systems.  In 
> one system I worked on, each channel had a 250 Hz low pass filter and a 
> 3400 Hz high pass filter at the transmit end.  This system was designed 
> to be "toll quality" which means that it would satisfy the end to end 
> requirements of the long distance telephone system.  So, 3150 Hz 
> bandwidth for a telecommunications channel which sounded "natural". With 
> guard bands, each channel was allocated a 4 kHz chunk of the spectrum.
> 
> There was also a requirement to pass "program material".  i.e. 
> commercial AM/FM radio broadcasts.  We had a way of using 2 channels for 
> this.  So a program channel, including guard bands, was allocated a max 
> of 8 kHz.
> 
> It is not obvious to me what normal ham radio SSB purpose would require 
> a bandwidth almost 6X greater than a good quality international 
> telephone circuit and 10X greater than the bandwidth I routinely use 
> when trying to communicate under difficult conditions.
> 
> In any event, I would expect that the transmit filters in any ham SSB 
> rig would have bandwidths far lower than that of the proposed microphone 
> so, if it costs more than a mic with a more restricted bandwidth, you're 
> spending money which could be put to a better use.
> 
> 73, Jim    VE7FO
> 
> Hans Remeeus wrote:
>> Hello,
>>
>>
>> The audio response of the PR-40 is 28 till 18,000 Hz. Would this be a 
>> bit too wide for normal SSB purposes?
>>
>> Many thanks in advance!
>>
>>
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