TenTec
[Top] [All Lists]

Re: [TenTec] Orion II - Initial Reactions and Impressions

To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Subject: Re: [TenTec] Orion II - Initial Reactions and Impressions
From: Robert & Linda McGraw K4TAX <RMcGraw@Blomand.Net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Wed, 28 Dec 2005 17:02:30 -0600
List-post: <mailto:tentec@contesting.com>
Ah, but the S meter should indicate a reference signal strength at the 
antenna input to the receiver.  Gain or no gain antennas simply means more 
or less signal.  A 50 uV signal should indicate S-9 regardless of antenna 
gain or loss.

With all the discussion of recent, I've looked at a couple of my radios 
using a HP 8656B generator of known accuracy with a precision 10 dB 
attenuator on the generator output to assure correct isolation and a true 
source Z of 50 ohms.  In all cases, all bands, 50 uV produces S-9 except for 
the Collins S-Line to which they use 100 uV for S-9.  As to levels below 
S-9, generally a 6 dB reduction in signal shows a reduction of 1 S unit. 
And a 10, 20 or 30 dB increase above 50 uV shows a reasonably accurate dB 
indication accordingly above S-9.

One point here is that the output of the generator must be maintained at 50 
ohms regardless of load.  Failure to achieve this, the generator output 
calibration may not be accurate as one is lead to believe.  Don't assume 
that the receiver input is actually 50 ohms.  It most likely is not.

73
Bob, K4TAX



----- Original Message ----- 
From: "Ken Brown" <ken.d.brown@verizon.net>
To: <gsm@mendelson.com>; "Discussion of Ten-Tec Equipment" 
<tentec@contesting.com>
Sent: Wednesday, December 28, 2005 1:24 PM
Subject: Re: [TenTec] Orion II - Initial Reactions and Impressions


> Geoffrey S. Mendelson wrote:
>
>>On Wed, Dec 28, 2005 at 08:21:03AM -1000, Ken Brown wrote:
>>
>>
>>>S-meter readings are already virtually meaningless.
>>>
>>>
>>
>>Yes, but what worries me is that almost all the time using the same
>>antenna. my Argo 509, Triton-IV digital, Drake TR-5, Kenwood TS-430s
>>and R5000 all read within one S unit of each other.
>>
> I should have clarified. S meters are virtually meaningless as signal
> strength indicators, because they are hooked up to antenna systems that
> vary over such a wide range of gains/efficiencies and in such a wide
> range of environments. S meters are however NOT useless. There are
> useful to compare from day to day, or antenna to antenna AT ONE QTH.
> They are not useful to compare readings from one QTH with differnt
> antenna systems and local conditions to another.
>
> DE N6KB
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec 


_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec

<Prev in Thread] Current Thread [Next in Thread>