[TenTec] Orion with V2 rf gain

Robert & Linda McGraw K4TAX RMcGraw at Blomand.Net
Fri Dec 23 19:02:19 EST 2005


The concept of RF gain vs. S meter has always been very strange to me.  If 
the S meter is to indicate relative signal strength then why should the S 
meter move up and down with adjustment of the RF gain control?  Speaking of 
ancient tube radios, and me being an AMer I have several, my Hammurland 
HQ-170A does not have the S meter move up and down when the RF gain is 
adjusted.  The S meter always indicates relative signal strength regardless 
of the RF gain adjustment.  And my Paragon and Omni VI Plus does not have 
the S meter move up and down when the S meter is adjusted.  Of course the 
signal level changes because the gain of the stages has bee reduced.

Frankly I dislike a radio that does this.   If I reduce the RF gain on my 
Collins 75S-3A then the S meter moves upscale as if there were signal 
present.  No longer is 100 uV equal to S-9.  (That's Collins reference.)  If 
the gain of the stage(s) is reduced then the gain should go down and the S 
meter should indicate the relative value of the signal for the available 
signal present.

I totally agree with Martin in his last paragraph regarding how the S meter 
should indicate relative signal strength.

73
Bob, K4TAX



----- Original Message ----- 
From: "Martin AA6E" <martin.ewing at gmail.com>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Friday, December 23, 2005 5:33 PM
Subject: Re: [TenTec] Orion with V2 rf gain


> We don't want beta testers to violate their non-disclosure agreements.
> They would have to sacrifice their first-borns, I think.  (Of course,
> the O II is now visible "in the wild".)
>
> The S-meter rising with lower RF gain is an artifact of how the RF
> gain control was implemented on ancient tube-type radios.  IIRC, it
> was by injecting a DC level into the AGC loop.
>
> I prefer the current (1.372) system, where the S meter stays constant.
> In my view, the S-meter should give you the best estimate of the
> actual signal level at the antenna connector.  When you insert RF
> attenuation, the S meter should not change, either. An S9 signal
> should be an S9 signal, no matter how you fiddle with your controls.
>
> It's a small thing, of course.  Have another glass of holiday cheer!
>
> 73 Martin AA6E
>
> On 12/23/05, Able2fly at aol.com <Able2fly at aol.com> wrote:
>>
>> _n4py at arrl.net_ (mailto:n4py at arrl.net)  writes:
>>
>> Tim,
>>
>> The RF gain control on the Orion II and Orion with V2 now  works like 
>> other
>> radios.  As you reduce RF gain, the S meter goes up  and the background 
>> noise
>> goes away.
>>
>> Carl Moreschi N4PY
>> >>>>>>>>>>>>>>>>>>>>>>>>>>>
>>
>>
>>
>>
>> Does that mean that Carl is an O1/V2 beta tester and knows how  Orion 
>> with V2
>> works? Tell us more Carl. Pleeeease.....
>>
>> ;-)  Bill  K3UJ
>> _______________________________________________
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>>
>
>
> --
> martin.ewing at gmail.com
> http://blog.aa6e.net
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