Best Icom 7300 Transmit Bandwidth TBW Settings

The Icom 7300 transmit bandwidth,TBW, has customizable settings. Sometimes it’s called the transmit filter width, not to be mistaken with the receive filter width. Have you changed your TBW to the best values? If they haven’t been tweaked, see how in this article and included video. I don’t have audio samples, sorry.

The 7300 isn’t the only Icom radio with this feature, my Icom 7000 also has adjustable transmit filter widths. It’s common in modern ham radio transceivers.

I had an excellent question posed to me in a comment and it got me thinking about TBW and the customizable values. The comment: “I read that some say “for DX, use a narrow bandwidth” whereas another says “Narrow setting does not work well for DX”. Problem is, I can’t figure how to “set:” the bandwidth they’re talking about.”

Transmit Bandwidth

Icom 7300 Transmit Bandwidth TBW – WIDE MID NAR

Do not confuse transmit filter width with receive filter width. Another friend of mine, Andy, WB0OAF, reminded me that these are confused at times. The receive filter width (not pictured) on the Icom 7300 is set using the FIL “soft button” on the LCD screen. Tap the FIL with your finger and you will see it change from FIL to FIL2 and then FIL3. These filter widths are adjustable also, but that’s another story.

The transmit filter widths are set using the FUNCTION, “hard button”, on the front of the Icom 7300. Push the FUNCTION button and a menu pops up (pictured above). You’ll see TBW. Tap TBW with your finger on the LCD and it will change from WIDE to MID and then NAR.

Look at the Icom 7300 Full Manual on page 4-14. The full manual can be downloaded from here.

Transmit Bandwidth

Icom 7300 Transmit Bandwidth TBW Customizable Values

Look at the Icom 7300 Full Manual on page 12-3. It is possible to set the transmission pass bandwidth of wide, mid, or narrow, by changing the lower and higher cutoff frequencies.

Push the MENU button on the front of the Icom 7300. Tap SET with your finger on the LCD. Scroll to find the “Tone Control”. Tap Tone Control and then tap TX with your finger. Tap SSB. Use the scroll up and down arrows on the right of the LCD screen to scroll up to page 1/2 (pictured above). In addition to TBW settings you can also adjust the TX Bass and TX Treble on this screen.

Transmit Bandwidth

Best Icom 7300 Transmit Bandwidth TBW Settings

What are the best settings? That’s a matter of opinion. Is narrow best for DX? I think so, because it takes out some of the low frequency. My narrow TBW is adjusted to reduce the high frequency too, thus compressing it more. But, it is subjective and each user can set their own values. I’ve asked around and here are some values being used by others:

The Default

SSB TBW (WIDE): 100 – 2900 Hz

SSB TBW (MID): 300 – 2700 Hz

SSB TBW (NAR): 500 – 2500 Hz

WIDE and MID High Frequency Altered (My settings)

SSB TBW (WIDE): 100 – 2900 Hz

SSB TBW (MID): 300 – 2900 Hz

SSB TBW (NAR): 500 – 2500 Hz

All High Frequency Altered

SSB TBW (WIDE): 100 – 2900 Hz

SSB TBW (MID): 300 – 2900 Hz

SSB TBW (NAR): 500 – 2900 Hz

Monitor Transmit Audio

How do we listen to the transmit audio? Great question! Using the Monitor on the Icom 7300 we can hear what it sounds like. Hook up your headset to listen.

Using the Monitor function isn’t really what your transmit audio sounds like on the air though, but it’s good enough most of the time.

If you really want to hear what your audio sounds like, have another Ham record and send the audio file to you. That’s the best way that I’ve found.

Included in this video: Demonstration of receive filter, transmit filter and customizing the transmit bandwidth. Also, suggestions for listening to your real transmit audio.

 

What do you think is best? Do you use NAR for DX? Please comment below, best 73 and good DX. – Rich, K0PIR

Sources for this article include comments by:

Wes, AI4FH

Andy, WB0OAF

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