(It’s also held in place with what I would describe as thick, (03) Remove the PCB securing screws (5) and put to one side.
(01) Disconnect the radio from everything and remove the bottom cover, exposing the ATU cover as shown. Remedial work involved carefully cleaning off this layer of lacquer I removed my ATU and was amazed to see that the tinned grounding pads were lacquered on the Issue, not firmware as so many have stated and centres around proper grounding of the ATU PCB. The fix I have come up with WORKS and now my 991/A behaves properly. I tried banging the radio on the lid and turning it upside down fixes it Upon deducing the two issues were almost certainly very closely related, So, irritated and confused, I searched the web then watched/read a number of cases detailing one, It told me theĪerial was much higher than 5:1 yet I knew my aerial was better than 2:1 at the band edges and Only by chance I had the 991/A internal meter set to SWR. I own a Yaesu FT-991/A and my 2016/17 build set started exhibiting low power out on 7MHz after tuning In both cases, an infinite SWR and the rig power set to ANY power level ONLY noticeable IF you have the rig meter set to SWR.
#Ftm 7250 d setup full#
Infinite SWR (5:1 or even full red scale), particularly on 7 MHz or lower. Some have even suggested a faultyĪ second fault is the internal ATU seemingly completing a tuning cycle but then presenting an Ideas from firmware, to biasing in an attempt to cure this. Many, including me, have looked at a number of The same radios back with the same fault again. Yaesu have diligently replaced these, only to have some users send
There have been published a number of issues with users stating their FT-991/A is blowing finals. This Compound has also proven to be better than what was used before.
While i had the mainboard out the chassis i took the time to apply a better Thermal Compound with a Thermal Conductivity of 11(W/m.k) RRP £14.99. As you can see the Yaesu FTM-100DR/DE has a better chassis as standard for better cooling as compared to the Yaesu FTM-400DR/DE.
#Ftm 7250 d setup mod#
Since doing this mod the radio stays a lot cooler than it did before and i've also noticed that the fan no longer stays on for as long as it did before the mod so there has definitely been an improvement. As you can see i've made 18 holes in the chassis between the fins and then turned the fan around so that it can draw the heat out from inside the unit as like the Yaesu FTM-100DR/DE does. The Yaesu (FTM-400XDE) that i now have has the same chassis as the Yaesu FTM-100DR/DE and also has the big vent hole as standard so no mod is necessary. I thought of doing this mod when i had the cover off my Yaesu FTM-100DR/DE when i was fitting the Yaesu FVS-2 Voice Guide Unit. I noticed that the Yaesu FTM-100DR/DE has a big vent hole behind the fan to allow a lot more heat to be drawn out from the unit but the Yaesu FTM-400DR/DE does not have this vent hole? no wonder quite a lot of people have been having heat issues with the Yaesu FTM-400DR/DE. The picture shows the mod that i've done to keep the temps down even better with the standard fan that's fixed to the rear of the radio. This is my modified Yaesu FTM-400DR/DE chassis.
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