Trish's FT-817 QRP Page

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817 Tweaks and Mods

Also reference our Projects page

Expanded TX
There is a mod out there to expand the TX range of the 817 for MARS/CAP use.  Since this mod offers the potential to mis-use the radio we are not including it on this site.  If you are a MARS/CAP authorized operator you should be able to find the mod info on the mods.dk website.

TX Power
There is another mod out there we hear talk of from time to time where one can increase the TX power from the factory rated 5 watts to 10 watts or more.  From what we've read the the finals in the 817 are rated at 8 watts each or a total of 16 watts as there are two of them.

While such a modification sounds very tempting, to have an 817 that can put out as much as the Elecraft KX3,you need to think things thru a bit before looking for and applying this mod.  Firstly, we've seen quite a few posts where people have set their 817 for 10 or 12 watts and fried their rig, do you want to risk frying your rig?  There is another train of thought, that you can make the power mod and safely use the radio at reduced duty cycle and avoid digital modes all together, is risking your radio and loosing digital really worth it?

Yaesu designed the 817 for a 5w output, it's designed to operate at 5 watts and to do so reliably.  The choice to buy an 817 is one made because we want the challenge of operating QRP.  If you're looking for a higher power rig that is portable consider the FT857 or the FT897, or perhaps adding an Elecraft KXPA100 ampliefer.  They're a little bigger than the 817 but you can run the power you are craving then.  We didn't mention the KX3 as an alternative to higher power as it's really only marginally more powerful than the 817 and still a QRP rig at least by some standards...

When testing our FT-817ND we discovered that, using multiple meters into a dummy load it was only putting out 4.5 watts.  Using the instructions for the TX power mod (thich BTW is done in software, there are no hardware mods needed) we adjusted our 817 so that it puts out an actual 5 watts.  We did not tweak the VHF and UHF TX power to 5 watts as our research suggests the finals operating in the VHF/UHF bands as they are from factory is already at their upper limits.

For reference for those who have made the power mod to something more than 5 watts and want to return their radio to a safe operating range you will find the factory settings for the TX power settings and those we used to acheive 5 watts output on our rig below.

HF1-IC, HF2-IC, etc reference the current sensing limit on the radio where if the radio sees a value higher than the setting in the menu it will automatically drop the TX power to protect the radio.  HF#-HI -L3, -L2, -L1 references the output power of the radio when select the power level via the "A" button just below the LCD display.  The HF# references a logical break up or grouping of bands in the radio that that setting applies to.  The Mhz Value i nthe table identifes the frequency we used in each of these "groups".

We've used color coding below to identify Factory Settings as RED, Factory Output Reading as GREEN, and Modified Setting in GREEN to achieve 5 watts on our specific unit.

1.885Mhz

Menu #18 HF1-IC = 72 New = 73

Menu #24 HF1-HI = 104 Output Reads ~4.4 W  New = 115 for 5W Output

Menu #25 HF1-L3 = 59 Output Reads ~2.2W

Menu #26 HF1-L2 = 22 Output Reads ~1.1W

Menu #27 HF1-L1 = 5 Output Reads ~.5W

Menu #48 HF1TXG = 66

7.269Mhz

Menu #19 HF2-IC = 72 New = 73

Menu #28 HF2-HI = 107 Output Reads ~4.6W  New = 115 for 5W Output

Menu #29 HF2-L3 = 59 Output Reads ~2.2W

Menu #30 HF2-L2 = 21 Output Reads ~1W

Menu #31 HF2-L1 = 5 Output Reads ~.6W

Menu #49 HF2TXG = 59

21.200Mhz

Menu #20 HF3-IC = 75  New = 76

Menu #32 HF3-HI = 104 Output Reads ~4.2W  New = 117 for 5W Output

Menu #33 HF3-L3 = 58 Output Reads ~2.1W

Menu #34 HF3-L2 = 21 Output Reads ~1.1W

Menu #35 HF3-L1 = 4 Output Reads ~.6W

Menu #50 HF3TXG = 64

50.100Mhz

Menu #21 50M-IC = 70 New = 71

Menu #36 50M-HI = 104 Output Reads ~4W  New = 115 for 4.5W Output

Menu #37 50M-L3 = 58 Output Reads ~2.1W

Menu #38 50M-L2 = 21 Output Reads ~1W

Menu #39 50M-L1 - 7 Output Reads ~.6W

Menu #51 50MTXG = 83

147.195Mhz

Menu #22 VHF-IC = 108

Menu #40 VHF-HI = 90 Output Reads ~4.2W

Menu #41 VHF-L3 = 50 Output Reads ~2.2W

Menu #42 VHF-L2 = 17 Output Reads ~1.1W

Menu #43 VHF-L1 = 5 Output Reads ~.7W

Menu #52 VHGTXG = 66

446.14Mhz

Menu #23 UHF-IC = 75

Menu #44 UHF-HI = 101 Output Reads ~4.5W

Menu #45 UHF-L3 = 58 Output Reads ~2.9W

Menu #46 UHF-L2 = 24 Output Reads ~1.1W

Menu #47 UHF-L1 = 6 Output Reads ~.6W

Menu #53 UHFTXG = 76

As with the MARS/CAP mod we choose not to provide instructions on how to change the TX power settings for the 817 as we do not wish to encourage people to make a change that could damage their radio or cause undesirable or illegal operation.  Mods.dk is the place for those who need to remember how to get into the hidden menus to change their radio back to safe factory default levels.