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George Byrkit edited this page Mar 6, 2023 · 5 revisions

Welcome to the DTMF_Shield wiki!

This project is devoted to the DTMF_Shield designed by Larry Anderton, WA7YLI, a number of years ago.

I, George Byrkit, K9TRV, have brought back his hardware design to be available again, and thanks to Larry we also have the original software installer and source code. That is available for download here, along with 2 variants: a more modern VB.Net version which was not used for long before creating the CSharp version. Current development by me is concentrated on the CSharp version.

Push requests are welcome. They will be seriously evaluated.

Right now, I'm busy reorganizing a few things, including cleaning up the need for 'fixDecimalSeparator()'. This is better done by using System.Globalization.CultureInfo.InvariantCulture to ensure strings contain a period for a decimal separator, and using System.Globalization.CultureInfo.CurrentCulture to transfer numbers to and from local string format. And being diligent about using these on Convert.ToString() and Convert.ToDecimal() and similar (such as String.Format).

As a result, I've ended up creating data structures (sometimes multiple) for each band module type and variant. Variant includes:

  1. whether or not 'European' band plan is to be implemented. This is expected for e.g. TM742E units, even when modified for 'wide band' operation by changing where 47k (473) 0805 SMD resistors are places on pads, as documented in both Kenwood service bulletins and some on-line resources (as mods). European band plan affects things like: 2m automatic repeater offset (plus or minus) plan, repeater tx offset, and band limits when not 'widebanded'. A variant would be to allow for J-type radios as well.

  2. whether 'wideband' has been selected on the control module for this band (by resistor change)

My other thrusts at this time are:

  1. to add support for the 'TM-2400' that was available in Japan. Werner, OE1RS,has such a unit.

    I have added support for the TM-2400 in the CSharp version. It shows great promise!

    I have implemented 'custom/odd/non-standard' split/repeater-offset so that the UT1200 and UT2400 are more useful in Europe. This involves allowing whole-MHz offset (+/-) up to 30 MHz from the receive frequency. Note that you need to program the CALL button on your microphone to be the 'MHz' button in the center of the VFO dial. Each channel can have its own custom/odd offset.

So item 1 has been pretty much implemented.

  1. to evaluate whether the TM-732(a) or TM-733(a) can similarly be programmed. To this end, a TM-732A has arrived today from eBay. However, it is less functional than I hoped; the front panel doesn't work (all segments on...), so this is delayed.
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