You can get a noise bridge from MFJ.  They sell their version and the one 
from Vectronics which are the same thing with different model numbers

I purchased one of both models in early June for $100 each.  They were out 
of stock when I order, however, in about 3 weeks I received them.  Probably 
don't manufacture a large stock.

While these noise bridges aren't a blindness related item specifically, they 
are very usable.  It seems that when we find items of use by blind people 
the items don't seem to stick around very long.  Probably because of low 
volume sales.

I suggest if you are interested in the noise bridges, order now and maybe 
get a couple.

73

Howard #3

----- Original Message ----- 
From: "Jim Gammon" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Saturday, August 10, 2013 12:58 AM
Subject: Re: Experience with Noise Bridges?


> Great, thanks Dave.  How much was it and from where did you
> obtain it? Jim WA6EKS
>
> ----- Original Message -----
> From: Dave Basden <[log in to unmask]
> To: [log in to unmask]
> Date sent: Fri, 9 Aug 2013 21:55:42 -0700
> Subject: Re: Experience with Noise Bridges?
>
> I have a new one from MFJ that is really a reseller for another
> company.  It is RF protected up to 300 watts I believe.  A relay
> is
> used to take the unit out of the circuit.  I used it to tune my
> external tuner for minimum SWR.  I had to turn the RF gain way
> down
> to hear the change in noise.  The noise pulses, but it is hard to
> hear the change with the RF gain up and AGC turned on.  I haven't
> used it much, but it worked fine for me.
>
> 73,
>
> Dave, W7OQ
>
>  At 03:33 PM 8/9/2013, you wrote:
> Ok, thanks Howard, I appreciate your information.  Will have to
> check with HRO to see if they even make them now.  73, Jim WA6EKS
>
>  ----- Original Message -----
> From: Howard Kaufman <[log in to unmask]
> To: [log in to unmask]
> Date sent: Fri, 9 Aug 2013 17:29:33 -0500
> Subject: Re: Experience with Noise Bridges?
>
> I used an old noise bridge 30 years ago.   It was very accurate
> with a deep
> null at the resonant point.  You couldn't transmit through it and
> it had RCA
> jacks.  I imagine they are better now.