ICOM Final Output Transistors for IC706MKIIG ICOM Final Output Transistors for IC706MKIIG Richard Eversole Wed Jan 1 03:38:37 EST 2014. Previous message:. Next message:. Messages sorted by: Depends upon the age of the 706MKIIG. There are two different sets. You can only get the newer transistors to the best of my knowledge. First units, used Motorola.SRF-J7044.

• Icom Ic 706 Mkiig
• Icom Ic 706mkiig Manual

MOSFETs. When they become obsolete, at about serial number 15xxx, Icom modified the final amplifier to use new devices, the (now) common.RD70HHF1. (HF/50) and the.RD70HVF1. (VHF/UHF). These transistors have a diferent case and can't be fitted to the old PCB without (at least) some physical mods.

SRFJ7044 are obsolete and almost impossible to locate, so only solution so far was to buy a new PA BOARD from Icom. From: Which has extensive instructions on repairing these transistors. Rick 'The Rhino' N6RNO @Tehama October 4-5, 2014 Where will you be? On Wed, Jan 1, 2014 at 7:32 AM, Floyd Petri wrote: Does anyone know the correct nomenclature and numbers for the Final Output Transistors for the ICOM IC-706MKIIG? And where they may be obtained reasonably? Floyd KF5YDH - This email is free from viruses and malware because avast!

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Icom Ic 706 Mkiig

706MKIIG Common Issues The DSP unit can get oxidized connections, resulting in garbled SSB operation/Mode mishaps/and dead modes (while other modes work fine) simply unplug the flex cable, and plug it back in, carefully. If you get a DC surge, there is a 4.7 ohm surface mount resistor on the bottom side of the PA unit, that is a fuse resitor for the regulators on the PLL unit. This is used in all the 706 series radio's, and the symptom is the radio won't turn on, and you hear a 'click' 'click' (relay closing and opening) Dead, no Rx/no Tx, check the 5v regulators on the PLL unit, there are 3 of them. Probably bad solder to one of them. Tx power is radically different on different bands, probably the detwector diodes on the filter unit. 706MKIIG/775(DSP)Finals These two, probably others, and any manuf.

Who used the J7044 MosFet for a final, have a terminal issue. The finals (SR(F or K)J7044(MP) are no longer available. I have tried to contact a few sources, and a couple of parts hunters.

No Stock, No availability. The PA in the MKIIG was changed in about 2004 to a newer (totally different RD70HV) device. You can swap out PA units for about $500! This includes the finals (no drivers)(706MKIIG only) A bit spendy, but at least there is a fix. The 775(DSP) has had very few cases of Final failure. The 775(DSP) PA unit is also pre-designed to use the MRF140's, the MKIIG cannot. The 706 MKIIG has had more cases of final failure than the 775, more MK2G's sold out there too, than the 775.

Beware buying used MKIIG's. The Serial number change is OLD 0xxxxx, Newer 15(or 16)xxxxx. I had the unique oppurtunity to evaluate the old 706 MKIIG PA unit and the new one.

The primary difference between the old final and new final, is the package. Performance criteria is actually almost exactly the same. The HF transformers and componets are the same between the two boards. The driver (old MRF1508, New MRF1518) is different on the new board, but is basically a newer design, with the same spec's. On the VHF/UHF side I was able to grind away enough board and fit the new final in place.

Icom Ic 706mkiig Manual

I needed to move the filter caps (input and output) closer to the body of the transistor, but otherwise it worked perfectly. This will not be as easy for the HF side of things, as one finals has quite a few bottom board side lands that would be cut or damaged.

If I get the chance to do this, I will report back on how it went. Here are some pic's of the VHF/UHF operation (note the transistor hole difference.