Peter:

   "Yes but not 1:1.4E6 attenuation in one step. They
     usually have several impedance steps afair? In my
     non-extensive experience achieving >50 dB attenuation
     of nearly anything in 'one step' is no go (assuming it is
     not tuned). Untuned one-step attenuators seldom go
     beyond 30 dB assuming that they are to be reproducible
     and untuned."

Two cases that work against any assumptions posted above:

1) I'm holding in my hand a Harris GSSD/PRD Instruments
    "Type X-101" , an X-band (10 GHz nominal) variable
     attenuator.

   Is is marked from 0 dB through to 60 dB. In my use of these
   and similar device made by HP I do not ever recall having
   'trouble' with the higher attenuation values.

   Of course, this does not use a 'switchable resistor' bank
   either ...

2) The attenuator on any of the Hewlett Packard 608 series
    of sig gens - these are marked on the dial from +7 through
    to -127 dBm. It does this in a continuous, un-stepped fashion
    with one mechanism - I have repaired this model before and
    can testify to the fact that it is one 'piece' which serves to
    couple ever-progressively less energy as the movable 'piece'
    is pulled ever further from it's mating assembly.

   I can attest that this device operates as billed too. These *is*
   leakage from the oscillator portion of this instrument, but it is
   *not* from the attenuator. Testing a fully shielded radio apparatus
    like the GE Mastr Pro line presents no problem from the leakage,
   testing a Japanese made HT or a poorly shielded 'scanner ' is
   another story.

Peter:
    "Even a simple cover joint with wire-clad gasket has two or
     three steps (depending on how you count).

To what is this applicable? (Microwave oven or choke joint)?

Jim

----- Original Message -----
From: "Peter L. Peres" <plp@ACTCOM.CO.IL>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Monday, August 27, 2001 4:31 PM
Subject: Re: [OT]:Microwave Oven


> > choke joint
>
> Yes but not 1:1.4E6 attenuation in one step. They usually have several
> impedance steps afair? In my non-extensive experience achieving >50 dB
> attenuation of nearly anything in 'one step' is no go (assuming it is not
> tuned). Untuned one-step attenuators seldom go beyond 30 dB assuming that
> they are to be reproducible and untuned.
>
> Even a simple cover joint with wire-clad gasket has two or three steps
> (depending on how you count).
>
> Apropos attenuation, any idea why a cellular phone works perfectly (S
> meter at 3 of 5 ?!) in a 4 x 2 x 2 meter welded steel safe with the door
> closed? Not all the seams are welded perfectly (this is not a submarine)
> but there are not enough bare wires to conduct the cellular signal inside
> at that level I think ?!
>
> Peter
>
> --
> http://www.piclist.com hint: The PICList is archived three different
> ways.  See http://www.piclist.com/#archives for details.
>
>

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.