Joined: 30 Apr. 2009
Karma Rating: 5
||Posted on: May 01 2009,01:36
The Yaesu FT-847 is a really amazing piece of kit...HF, 6m, 4m, 2m and 70cms, all mode, and with twin VFO's in a relatively compact radio thats just as at home as a homebase radio as it is as a mobile radio.
The power output of the FT-847 on VHF and UHF is actually higher than almost any other HF/VHF/UHF multiband ham radio, ie: 100watts on HF, 100 watts on 6m, 85watts on 4m (see below), 50 watts on 2m and 50watts on 70cms,
The UK spec FT-847 remains the ONLY Japanese made amateur radio transceiver that offers 4m as standard. Yaesu stupidly stopped production about 10 years ago so now they are very sought-after rigs, with used ones often fetching as much as a brand new FT-897!
I find the HF RX performance to be a lot better than some reviews led me to believe it would be, and its bleedover rejection is certainly no worse than any similar multiband radio.
In standard UK spec the FT-847 gives out just 10 watts on 4m but with a heavy power consumption of around 20 amps. Fortunately there is an extremely simple mod that was discovered by Dutch Ham, and electronics genious, Marc Vlemmings (PA10) that offers a nearly perfect solution...It basically involves removing a single 450pf SMD capacitor (C5051) and then snipping one little wire on the other side of the radio (thats goes to the ALC transistor)...and thats about it!
The results are a maximum output of around 85 watts on 4m but at a much reduced power consumption of around 16Amps and the power consumption at 100 watts on 6m also goes down from 21Amps to around 17Amps as well!
I can only think of two minor niggles, ie: The volume control takes some getting used to as nothing can be heard until its turned to around the 8.30 position then it suddenly comes on and at a volume that is a bit loud for late night use when others are asleep...Headphones are a good solution. (BTW, dont ever be tempted to do the KB2LJJ volume control mod as it will almost certainly damage your FT-847!)
The FT-847 is sometimes criticised for its annoying cooling fan whine...It actually has two fans that run constantly when the radio is switched on (an internal fan at the front of radio and an external fan at the rear of the radio), which both speed up on TX. Most of the noise comes from the rear fan...I can confirm that the rear fan can simply be disconnected without the radio getting noticably hotter, thus greatly reducing the fan noise...The interior fan seems to be all that it needs to keep cool.
All in all the FT-847 is probably the only rig you will ever need and I give it a big thumbs up