Digipan 2.0 questions

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Andrew Lane Frazier:
New user to Digipan 2.0 and PSK31 and I have not found the answer to these questions by reading the help files. Rig is IC-718 Interface is Signalink USB

I have been reading a good bit about not overdriving the PSK31 signal etc. My question is about IMD. I know that you cannot see your own IMD but only those which you are receiving...

Q1. My issue is that I never see a number in the IMD box at the bottom of the Digipan screen..It always stays blank. Is there some option I have to enable to see an IMD number?

Q2.On the bands configuration option. Here you can set a freq for each band..what I need clarification on is using the 3 bullets to the right...one for tone..USB and LSB...the default seems to be tone...

I thought you used usb for psk31. What is the purpose of the  3 options and why would it default to tone?

Thanks for your help
W5ALF

James "Scott" Duckworth:
Q1. My issue is that I never see a number in the IMD box at the bottom of the Digipan screen..It always stays blank. Is there some option I have to enable to see an IMD number?

Normally, once you click on a station trace in the waterfall, you will see the IMD. It could flash off and on, and if I remember right, if you click the IMD window, it will pause or freeze (that is if I remember right).

Q2.On the bands configuration option. Here you can set a freq for each band..what I need clarification on is using the 3 bullets to the right...one for tone..USB and LSB...the default seems to be tone...

Well, tone is simply the tone frequency. The USB and LSB are set band specific (say USB for 20M, LSB for 40M) and you set the RF frequency in the setup to reflect the "start" frequency on the left side of the waterfall. Here is what is in the help file about it:

"Band This opens a dialog for setting the spectrum start frequency for the dial scale display of actual RF operating frequencies in either USB or LSB. When using LSB, enter the highest desired frequency, and when using USB, enter the lowest desired frequency. Digipan then scans the rest of the PSK31 portion of the band automatically and displays any stations found there. The spectrum start frequency must be entered in kHz, or kHz plus tenths of kHz, such as 14073, or 14073.1, or 14072, or 14070, or 14069, etc., as described in more detail in Setup."

and this after going to the "Setup" mentioned above:

"Setting up the DigiPan dial scale to read actual transmitted RF frequency:

Under Configure/Band, mark the band you wish to be displayed on the dial scale as active, tab to the Spectrum Start box and enter the Spectrum start frequency in kHz, or kHz and tenths of kHz, and check if you want the dial scale to display the Tone frequency, USB, or LSB. If you select USB, the Spectrum start frequency to enter is the low end of the band segment you want to cover and if you select LSB, it is the upper end of the band segment. It is important to note that the Spectrum Start frequency is the "zero beat" frequency, which is the same as the transceiver dial setting, so it is suggested that the Spectrum start frequency, and accordingly the transceiver dial, be set about 0.5 kHz away from the first desired frequency of operation.

As an example, for 20 USB meter operation starting at 14070,

Enter 14069.5 as the Spectrum start frequency.

Set your transceiver dial to 14.069.5 MHz and DigiPan will tune from 14.069.5 MHz
to 14.073 MHz for you. Do not touch the transceiver dial after setting it and the DigiPan dial scale will read correctly. Assign the frequency to a memory if you have one. Use the widest IF filter available. If the IF filter is 3.5 kHz wide, stations between 14.070 and 14.0730 should be workable. If the IF filter is only 2.5 kHz wide, stations between 14.070 and 14.072 will be workable. Even though it may be possible to copy strong stations somewhat outside the filter bandwidth, attempted transmission too far from the filter passband will usually result in operation at greatly reduced power levels.

If you need to use LSB, check LSB, set the transceiver to 14.073 MHz, and the Spectrum Start frequency to 14073.0 kHz, and DigiPan will tune down 2.5 kHz or the width of the IF filter for you.

DigiPan will remember the dial scale settings you enter, so when you change band, it will usually only be necessary to select the active band and the dial scale will read correctly.

You can edit the default Band and Spectrum start frequency to any band and any frequency and the DigiPan dial scale will read correctly, as long as the frequency is entered in kHz.

Just remember to always set the Spectrum start frequency and the transceiver dial frequency to the same value and select the same sideband on each."

Hope that helps. I can promise you, once you learn Digipan, you will have a lot of fun. My station here does a lot of digital on amateur and MARS frequencies, using PSK31, RTTY, SSTV, MT63, Olivia, and the new EasyPAL digital SSTV, as well as APRS and packet on VHF.

de NA4IT

W Sanders:
A1: IMD is only measurable if the other station is transmitting an idle "carrier", You will see the figure automatically appear when the other station is idle, as is often the case at the beginning and end of a transmission.

A2: These three menu items determine whether the display shows the audio frequency, USB, or LSB operating frequency offset with respect to the tuned frequency of the radio. This displayed frequency is also used by the logging capabilities of the program, and is available in macros. PSK31 is symmetrical with respect to sideband, so USB vs LSB is mostly a matter of habit or of eliminating adjacent signals.

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