Not true,

While the noise bridge can survive up to 300 watts, it is not intended to be 
left on.  There is a relay that senses RF and bypasses the bridge if you 
forget.  The relay will go nuts if you leave the bridge turned on.  Not 
intended to use turned on!!

Howard #3

---- Original Message ----- 
From: "Dave Basden" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, January 01, 2014 3:24 PM
Subject: Re: Using MFJ Noise Bridge To Determine Antenna Resonant Frequency


> Hi Tom,
>
> If the noise bridge is between the TS-590 and the amp, you shouldn't
> have to worry about running too much power into it.  It's only when
> the bridge follows the amp that you would have to make sure the switch is 
> off.
>
> 73,
>
> Dave, W7OQ
>
> At 10:43 AM 1/1/2014, you wrote:
>>Lloyd:
>>
>>I think Howard and Lowell have answered this question, if I'm interpreting
>>their posts correctly.
>>
>>Apparently, if the switch on the noise bridge is off, one can use the
>>amplifier without any risk to the device.
>>
>>Tom Behler: KB8TYJ
>>
>>
>>-----Original Message-----
>>From: For blind ham radio operators [mailto:[log in to unmask]]
>>On Behalf Of Lloyd Rasmussen
>>Sent: Wednesday, January 01, 2014 12:12 PM
>>To: [log in to unmask]
>>Subject: Re: Using MFJ Noise Bridge To Determine Antenna Resonant 
>>Frequency
>>
>>I would put the noise bridge in the line between the transceiver and the
>>amplifier.  This would prevent it from seeing your 600 watts.  I don't 
>>know
>>about the on-off switch.
>>
>>
>>
>>Lloyd Rasmussen, Kensington, MD
>>http://lras.home.sprynet.com
>>-----Original Message-----
>>From: Tom Behler
>>Sent: Wednesday, January 01, 2014 11:40 AM
>>To: [log in to unmask]
>>Subject: Re: Using MFJ Noise Bridge To Determine Antenna Resonant 
>>Frequency
>>
>>Bob:
>>
>>Ok on not using both the manual and internal tuners together. ... This is
>>what I suspected.
>>
>>Ok also on confirming Howard's procedure for determining the resonant
>>frequency of an antenna using the MFJ noise bridge.
>>
>>Now, I have one more question:
>>
>>Here in the home shack, am I correct in saying that I'm ok with keeping 
>>the
>>noise bridge in the circuit at all times, as long as I am absolutely 100%
>>sure to turn the noise bridge off before transmitting with 100 watts, and
>>especially before tuning and then using my AL811H amplifier?  The amp puts
>>out about 600 watts, and I know the Noise Bridge only handles 300 watts. 
>>I
>>realize that the noise bridge has a protective circuit, but I have learned
>>over the years not to totally trust those protective circuits.
>>
>>Tom Behler: KB8TYJ
>>
>>
>>-----Original Message-----
>>From: For blind ham radio operators [mailto:[log in to unmask]]
>>On Behalf Of Bob, K8LR
>>Sent: Wednesday, January 01, 2014 11:20 AM
>>To: [log in to unmask]
>>Subject: Re: Using MFJ Noise Bridge To Determine Antenna Resonant 
>>Frequency
>>
>>Tom,
>>
>>The noise bridge works very well in getting your SWR down to 1-1.  The
>>really nice thing about the MFJ212 and the VEC512 is that you can transmit
>>with the noise bridge in line with a power of up to 300 watts.
>>
>>I would not use your 480 internal tuner if your running an external tuner.
>>That combination could cause some really high voltages at the antenna
>>connector that could pop some components.
>>
>>Howard has got it right on how to find a resonant frequency with the noise
>>bridge.
>>
>>Bob, K8LR, [log in to unmask]
>>
>>----- Original Message -----
>>From: "Tom Behler" <[log in to unmask]>
>>To: <[log in to unmask]>
>>Sent: Wednesday, January 01, 2014 9:49 AM
>>Subject: Using MFJ Noise Bridge To Determine Antenna Resonant Frequency
>>
>>
>>Hi, again, everyone.
>>
>>
>>
>>Sometime late last Summer, someone on the list suggested that an MFJ 212
>>Noise Bridge might be useful for determining the resonant frequency of an
>>antenna, even one that might be resonant outside the ham bands.
>>
>>
>>
>>Is this possible, and, if so, how exactly might that be done?
>>
>>
>>
>>Tom Behler: KB8TYJ