This is an old revision of the document!
30 meter mod for the Omni D
References
- Tentec's WARC band mod instructions warc_install.pdf
Introduction
The World Administrative Radio Conference approved the WARC bands at nearly the same time as Tentec developed the Omni 545 and 546 - 1979. The original Omni series came with 10.0-10.5 MHz receive only. A kit was later offered to upgrade the series to 10.1 MHz (30 meters) transmit and 24.89 MHz (12 meters) receive and transmit. As of this writing (2017), the kit has been unavailable for some time. 18.068 MHz (17 meters) was not offered, because it was a multiple of the Omni's 9 MHz carrier oscillator, and would have had unacceptable spurious output.
This mod is a partial duplication of the WARC mod, for 30 meters only. Tentec encouraged amateurs to perform this mod themselves in the kit instructions. However, as parts are no longer available from Tentec, substitutes were developed. Omni owners contemplating this mod should see the instructions at warc_install.pdf to familiarize themselves with the steps. In particular, the steps listed under the heading "SUBJECT: Modification to permit operation on 10 MHz band only" should be read. Most of the disassembly information will not be repeated here. The mod is "no tune", so no alignment is necessary.
Click any image for an enlarged view.
Bandpass board, bottom side, showing pads for 30m mod:
Bandpass board, top side, showing finished 30m filter mod (between bandswitch and the shield can at the right):