Yaesu FT290R for TXV use

Yaesu FT290R for TXV use
Ham Radio
Once in a while I see questions about the use of an FT290R for transverter use.

I have an Yaesu FT-290R, about 12 years old. The look-alike rig for 70 cm is the FT-790R. If I'm correct, the PLL-system was exactly the same (exept for the X-tal for mixing up).
It could well be that the mark II versions still use the same processor type.

The information was printed in the VERON DX-press/VHF-bulletin abt 11 yaers ago. I don't know the author or the exact year. The primary intention of the publication was using an FT-290 as transverter for 70 cm.

The information concerns the microprocessor chip 'HMCS45C' probably noted as Q01. On the pins 38, 39, 40 and 41 jumpers to ground specify the freqency-range, preset and step. With 4 pins there should be 16 different combinations. The factory set position determins the version for European or US-market.

In the table below you find the known combinations for the FT-290R. 'X' means jumper to ground.
My guess is that removing the jumper at pin 39, the PLL is transformed to a wider frequency range used in the FT-790R. Once you are able to reach the print-board, you could try to (de)solder the jumpers and determin the results.
These modifications are best made with power and battery backup switched off.
band  ¦ 144-146  ¦144-148  ¦143.5-148.5¦ 144-148 ¦145-146 ¦144-148
preset¦ 145      ¦145      ¦146        ¦ 147     ¦145     ¦145
step  ¦ 12.5/25  ¦12.5/25  ¦5/10       ¦ 5/10    ¦10/20   ¦5/10
41    ¦ X        ¦         ¦X          ¦         ¦        ¦
40    ¦          ¦         ¦X          ¦ X       ¦        ¦X
39    ¦          ¦         ¦           ¦ X       ¦X       ¦
38    ¦ X        ¦ X       ¦X          ¦ X       ¦X       ¦X

        I hope this information is of some use.

        Best 73, good DX and perhaps we meet in an direct QSO.

        Tom PA3DXV @ PI8JOP

        QTH: Sittard, JO21WA

GW1NGL NA7KR Kevin Roberts Ham Radio
GW1NGL NA7KR Kevin Roberts Ham Radio

Page last updated on 09/10/2012 by Kevin Roberts NA7KR a colection of Ham Radio and Electronic Information