[TenTec] cw creation

Steve N4LQ n4lq at iglou.com
Sun Apr 24 21:18:49 EDT 2005


I think the newer DSP rigs would be classed as A1A. Rigs like the Omni VI 
have DSP but carrier originates in a conventional oscillator so it too would 
be A1A. The Collins 32S is the only J2A rig I know of but I have a feeling 
there were others. Maybe someone else can fill in the blanks.
Steve Ellington
N4LQ at iglou.com
----- Original Message ----- 
From: "Bob Stephens" <bstephens1 at mindspring.com>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Sunday, April 24, 2005 8:41 PM
Subject: Re: [TenTec] cw creation


> Steve,
>
> You write, "When you tap the cw key, you are actually causing The DSP to
> run a process that results in the DSP stage outputing an 11khz carrier"
>
> That does not sound like "injecting a tone". What you describe sounds like
> A1A emission - turning a carrier on and off . Obviously, this is at a 
> lower
> frequency than the classic method, but it still sounds like the carrier is
> being keyed on and off thus it appears to be A1A rather than J2A .
>
> Was Shelby Enis, W8WN wrong when he wrote "Keying is done by an injected
> audio tone...The emission type is designated J2A ... and is the same 
> method
> used by many rigs to produce cw "?
> Or perhaps I am misunderstanding him ? (his full quote is at the bottom)
>
> tnx & 73, Bob KB1CIW
>
> At 08:07 PM 4/24/2005 -0400, you wrote:
>
>>The DSP stage in many modern rigs actully contains the entire radio. The
>>rest of the rig converts the DSP's output to the right frequency. SSB, 
>>FSK,
>>CW, AGC, Detection is all done inside the DSP stage. The input and output
>>frequency of this DSP stage varies. The Jupiter/Pegasus DSP uses 11 khz 
>>for
>>I/O. This means that the other conversion stages in the rig must convert 
>>the
>>ham bands down to 11 khz for reception and back up for transmission. When
>>you tap the cw key, you are actually causing the DSP to run a process that
>>results in the DSP stage outputing an 11 khz carrier. This carrier is then
>>converted to the ham bands and amplified. This is a far cry from "feeding
>>audio into a mic. jack"!
>
>><snip>
>
>>Am I making sense?
>>Steve Ellington
>>N4LQ at iglou.com
>>----- Original Message -----
>>From: "Bob Stephens" <bstephens1 at mindspring.com>
>>To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
>>Sent: Sunday, April 24, 2005 7:31 PM
>>Subject: Re: [TenTec] cw creation
>>
>>,snip>
>>
>>... an article about High Speed CW for Meteor scatter work called
>> >>"Utilizing the Constant Bombardment of Cosmic Debris for Routine
>> >>Communication" by Shelby Enis, W8WN He explains how "cw" is produced as
>> >>used in one type of meteor scatter work and he writes:
>> >
>> > "Keying is done by an injected audio tone [using sound card technique] 
>> > (as
>> > is done with many of the digital modes), ...<snip>. The emission type 
>> > is
>> > designated J2A. This method produces keying that is indistinguishable 
>> > from
>> > on/off keying of the main carrier, and is the *same method* [my 
>> > emphasis]
>> > used by many rigs to produce CW."
>> >
>> > So, let's see if I understand this correctly . In many modern rigs 
>> > keying
>> > is done by audio type keying that results in J2A rather than true A1A
>> > emission. On the receiver end we can't tell the difference. This was 
>> > first
>> > done unsuccessfully in the Collins. In modern rigs today this is often
>> > successfully done using  DSP. Is this basically true?
>> >
>> > Questions:
>> > 1.Can I assume that the Orion, Jup/Peg and perhaps the 756/746 are all
>> > producing J2A?
>> >
>> > 2. Can non DSP rigs be used to transmit legal J2A if sound card 
>> > technology
>> > is used ?
>> >
>> > 3. Were there other rigs (besides Collins) that used audio type keying
>> > without DSP? Is DSP the only way to produce clean legal J2A ?
>> >
>> > 4. Can I assume that the classic TT rigs produce A1A and not J2A?
>> >
>> > 5. I still don't really understand what J2A audio type keying is. What 
>> > is
>> > the difference between J2A and simply keying the rig in SSB mode while
>> > holding the microphone to the output of a code practice oscillator?
>> >
>> > It is possible that I'm totally clueless <grin> ... and so I ask 
>> > questions
>> > ;-)
>> >
>> > tnx & 73
>> > Bob, KB1CIW
>> >
>> >
>> >
>> >
>> > --
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>> >
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