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Author Topic: FT-857D - Rejecting Adjacent Interference  (Read 413 times)
WU6X
Member

Posts: 12




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« on: November 08, 2007, 07:34:44 AM »

If you have one of these radios, you may have discovered that factory settings are not optimized for some things ... adjacent channel (SSB) interference is one of them. You can help the receiver be much better at rejecting nearby SSB signals by changing the following:

Menu-047 DSB LPF CUTOFF comes set at 6000hz, but can be adjusted as low as 1000. I set this to 2450hz (the manual recommends 2130-2770).

This made a remarkable difference on loud adjacent signals. The receiver acts more like a desktop radio now, with loud signals not heard if more than 2.5-3khz away, and just barely at 2khz.

On CW, use the DSB "DBF" control (DBF Width Menu-045). Set to 240hz (or 120hz). This works very well ... no need to buy extra filters. However, you must tune a CW signal to the "spot" frequency (ie. "blue light" flashing) to be inside the DBF passband.
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N5EAT
Member

Posts: 175




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« Reply #1 on: November 08, 2007, 01:37:41 PM »

I agree.  I use the 857 in my car, and have made similar adustments.  It really cuts down on the general receiver hash too making the rig pretty quiet.
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