If you accidentally fire RF in through the out door and find the receiver has gone deaf, don’t despair! There is a 8v 100mA bulb soldered to two pins on the board which acts as a fuse. Yaesu rigs are notorious (I now know) for their lack of overload protection – the printed circuit board is the overload fuse and the result is a dead rig! Fortunately it wasn’t too difficult to find the problem and fix it – see below for more details.Īfter encountering a power drop to 50w, I did some digging and with help from HP1KL (Tony Conte), M0BCG (Ian WIlliams) & G3LLL (Harry Leeming) I have gathered together this info here. This turned out to be disastrous – MY ADVICE NOW IS NEVER USE THIS SOCKET! In my haste I didn’t test the power lead, which unfortunately has a short-circuit in it. I thought the best place to power this from would be via the ancillary power outlet socket on the back of the rig. When I acquired a new power/swr meter, I noticed the dial was a bit dim so a back light has thoughtfully been provided. The power level on ssb can be run at 200mw now if I want! Thankfully it was simple to do and very successful.
#Yaesu Ft 757Gx Problems mod#
The mod involves removing the crystal filter and then snipping a diode on the main board just underneath the crystal filter, labelled D099. I found a mod on the web to re-enable the PA-drive control in SSB which allowed the rig to be used in a similar manner to most other rigs and with much better power precision. This can hinder accurate power control such as is needed when I need to run 1 watt into a 6m transverter. Having said that, I’ve worked S.Africa, S.America, Asia and Australia on 40m so it can’t be such a limiting factor!Īs standard, the PA-drive control is disabled in SSB (it isn’t on AM or FM). In theory I thought that might give me a chance but it only helps a tiny amount. I’ve tried various tricks, such as using split transmitting (in SSB mode) and receiving (via the CW narrow filter). It could do with more effective IF filtering but this is why you buy a more expensive rig of course! During busy times on 40m, operating can be very limited by QRM.
The receiver is sensitive and most of the time I’m really happy with it.
My first outside-G contact was on 20m with 10 watts to France…on AM! FM has also received good reports. Never had any complaints about SSB modulation and often get complements on the audio using the original MH-10B fist mic. The Yaesu FT-747GX was manufactured in the early 1990s and was the smallest HF transceiver of its time, with a nickname of ‘plastic fantastic’! The transmitter gets good results generally.