[Top] [All Lists]

Re: [Yaesu] FT890 strange behavior

To: <kz8e@wt.net>, "Michael Tortorella" <w2iy@verizon.net>
Subject: Re: [Yaesu] FT890 strange behavior
From: "Paul" <w8aef@q.com>
Date: Thu, 11 Jul 2013 10:02:00 -0700
List-post: <yaesu@contesting.com">mailto:yaesu@contesting.com>
Excellent advise.

de Paul, W8AEF

-----Original Message----- From: Earl Morse
Sent: Thursday, July 11, 2013 6:52 AM
To: Michael Tortorella
Cc: yaesu@contesting.com
Subject: Re: [Yaesu] FT890 strange behavior

Rather than pile $25 worth of ferrite and filters on it why not take a divide and conquer systematic approach to resolving the problem.

Start with the supply. Can you draw 20-30 Amps out of it with just a plain resistive load? If not, the supply may be defective without even adding the RF part into the equation.

Next add the radio without all the microphones, CAT interfaces, external speakers, etc connected. Transmit into a dummy load at a low power level. Do you notice the issue? Check all bands. If the issue is still non existent increase power and repeat checking all bands. Check CW and Modulated modes.

If the issue is still not recurring start adding the microphones, head phones, speakers etc back into the equation and recheck functionality to see what it takes to make that power supply fold up.

The final stage will be adding the antenna and transmitting full power with everything hooked up.

Once you know exactly what it takes to make the supply fold up it is going to be much easier to determine the exact fix. Adding a ferrite bead (what mix??) to attenuate common mode currents when you are uncertain about which frequencies or which cables are even causing the issue (1.8-30 MHz is a big chunk of spectrum)is more of an exercize in how lucky you are rather than how good you are.

Good luck with the process.  Let us know how it comes out.


Yaesu mailing list

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