[TenTec] ORION BCI

[Martin, AA6E]

Stuart,

As I read the schematics, the Orion should be OK up to about 10 Vpp of
RF, before the clipping diodes start conducting.  (They are reverse
biased.) Maybe something else will go nonlinear first, like the diode
switch.  I agree that having the attenuator first would be a help.

73 Martin AA6E

On 5/27/05, Stuart Rohre <rohre at arlut.utexas.edu> wrote:
> Martin, I did mean in line as series to the antenna connection.
> 
> Clearly, having diodes ahead of an attenuator is going to do no good in
> strong RF fields.   By strong, I mean 3 blocks from a daytime 25 kW station
> you can get 10 volts per meter.   That is what we have at the research lab
> where I am.
> 
> The diodes are going to conduct after 0.6 volts if silicon, and if no series
> resistor raises their ability to conduct.  Then you have non linear products
> of all the RF coming in.
> 
> Perhaps there is a bad diode in the protective circuits.  From all the
> descriptions of problems on this one Orion, it sounds like an anomaly.
> There are contesters using Orion with NO problems, they have posted in other
> forums.
> 
> -Stuart
> K5KVH
> In our RFI testing, the attenuator goes right after the antenna, then the
> receiver circuits.
> 
> 
> 
> 


-- 
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