What does switching to digital mode on Yaesu Xcvr's (or any other HF radio) actually do?

The documentation states that "specific digital mode selections, which include custom BFO offsets to optimize the receive and transmit passbands for the mode selected".

So the context of this question is a friend whom recently purchased an FT-840 HF Xcvr which doesn't have a digital mode selection to speak of. How can he tune his radio to match the performance of a radio with a digital mode option? Besides BFO offsets, what else does digital mode do, and how would one mirror that same configuration on a radio without "digital mode"?

Page 36: Digital Mode selecion : PSK31-L or PSK31-U http://www.download.n7tgb.net/yaesu/ft897/ft-897_operating_manual.pdf


2 Answers 2


I can't comment from experience on other Yaesu transceivers, but the "Digital" mode on the Yaesu FT-857/897 is basically a second SSB/CW mode. It exists in order to have a separate, configurable group of settings so that you don't have to change your regular settings away from those suitable for SSB phone use.

If I remember correctly, it includes the following separated settings (adjusted separately vs. other modes) or special settings (adjusted with “digital”-specific menu items):

  • Upper vs. lower sideband
  • Offset between the displayed frequency and carrier frequency (SSB phone normally displays the carrier frequency; CW displays the center of the passband; the Digital mode lets you set an arbitrary offset.)
  • DSP filter passband edges
  • IF shift

If another radio has these settings, then it can be configured the same way. The "digital mode" is merely a convenience to enable all those settings at once; it does not have any unique capabilities (other than the arbitrary frequency offset) and does not involve anything like a modem.

Other models or brands of transceivers might use the term differently, such as by actually implementing digital modes (modems) directly in the transceiver.

  • $\begingroup$ In addition to this, "Digital" mode also often enables a flat EQ setting (no adjustments for voice clarity) as well as disabling any noise reduction settings that might be enabled in normal SSB mode. $\endgroup$
    – KC4K
    Mar 4, 2016 at 20:42
  • $\begingroup$ Did you mean FT-897? The 857 and 897 form a pair in terms of transceiver design. I don't think I've heard of any FT-987. $\endgroup$
    – user
    Mar 6, 2016 at 22:38

On my Elecraft Digital is called Data - and because the Radio has in-built capabilities to handle digital (Tone Signals) modes, and I suspect that this is the case on some of the higher end-models from Icom, Yaesu and probably Kenwood.

For example using the mode PSK-32, you want minimal signal compression (as it causes splatter) - so you need to adjust the Mic-Gain and the Compression of the audio from you transceiver - but if you QSY (Change frequency) to somewhere else and are now in a part of the spectrum (frequency allocation) that allows Voice - You now want compression, and higher mic-gain (It makes your voice sound better/clearer)... instead of going through the tedious setup routines (as Kevin previously stated) - you just switch modes.

Power settings can differ between CW/SSB and Digital modes - some modes are only wanting to use very very small amount of power J65 - whereas others - RTTY it is Full-Blown linear amplifiers and high gain Yagi's.

The most difficult thing regarding digital is interfacing your PC (An Elecraft can send some digital modes using a CW key - assuming you are proficient at CW) to the radio. Once you have accomplished that - then Digital just takes a little time to figure out what mode, software and setup you need.

  • $\begingroup$ What do you mean by "An Elecraft can send some digital modes using a CW key" ? $\endgroup$
    – LCS
    Mar 5, 2016 at 13:16
  • $\begingroup$ Elecraft radio’s (K3, KX3) are designed to be used portable, and so for me I can change the “mode” on the radio to Digital (actually [DATA] in Elecraft) - I now select the “Digital” mode - and I will pick PSK-32 - now using a CW key I can send morse code i.e. -.-. - -.- (CQ) and the K3/KX3 will generate the PSK tones and transmit them. When I listen to the other station there is a built in decoder which shows a scrolling 7-8 characters of what the other station is sending. The Elecraft option is great is you are working /P or just want a little Digital - but you would NOT attempt a contest. $\endgroup$
    – Tim Seed
    Mar 5, 2016 at 13:49
  • 1
    $\begingroup$ Ok got it! But did you mean PSK31? $\endgroup$
    – LCS
    Mar 5, 2016 at 13:58
  • $\begingroup$ Opps - sorry typing and watching the football !! You are most correct $\endgroup$
    – Tim Seed
    Mar 5, 2016 at 14:58

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