Taming the Yaesu FT-857D for Rover Use

Repairing my FT-857D Transceiver

Sooner or later Murphy's going to get you! 
After using this rig for one contest (Jan. 2011) the maximum power output on 6 meters dropped to approx. 22 watts (100 watts normal) and peaks with an RF Power Setting of 40 (menu #75) using CW or FM modes. Grounding the "QRP" wire in the power cable reduces the CW or FM power output to 12 watts maximum. The AM maximum power is 12 watts (3 watts "QRP"). ALC indicates modulation on SSB.

Checking the other HF bands indicates that they are also running at reduced power however both the VHF (144 MHz) and UHF (432 MHz) power outputs are within specifications. All of the operating menu (and service menu) settings are normal. All power outputs were measured at 14 VDC with a Bird meter and 1:1 SWR dummy load.

So, it's off to find a repair shop. In the past I've used both the national Yaesu and local Burghardt repair shops. I'm sure that there are others out there:

• Yaesu Vertex Standard USA
• Burghardt Radio Repair

 Shipped to Burghardt on 5/26/11, stay tuned for the results! 
According to Jim (at Burghardt) the radio had suffered a high power spike; probably resulting from the close proximity of antennas while the yagi stack was "nested" (mast retracted). The 100W outputs from 2, 1.25 and/or 0.7 meters may have entered the radio via the 6 meter antenna causing extensive component damage. Note that the 70 cm per-amp located within the external amplifier was also blown!
Click here to read about my solution to this problem.

>>>Jan. 2013 Update: I used my repaired Yaesu FT-857D during the VHF contest. It performed flawlessly! I really like this rig for running the 4, limited-rover bands (50 - 432 MHz) with an external DEMI transverter for 222 MHz.  Of note are the DSP performance on both SSB and CW as well as the easy band and mode switching. I ran 6 meters with the internal 100W power output while using external 100W amplifiers on the 144 - 432 MHz bands. The "CW auto mode" (menu # 022) allows the CW key to be enabled even when you're in SSB mode.  This saves a lot of time when you need CW in a pinch!  Also note the full band-selected encoded BCD that's available on the CAT/Linear/Tuner output jack when "Linear mode" is selected (menu # 020).

My transceiver selection criteria consisted of:

1. Affordable
2. Remote control head
3. Built-in 100 watt amplifier on 6 meters
4. Adequate drive power for external amplifiers on 2 and 0.7 meters
5. Separate power output adjustment for each band
6. Controllable, low-level power 28 MHz IF for driving an external, 1.25 meter transverter (via ALC)
7. Ease of use and reasonable user interface
8. Highly effective noise limiter and IF DSP filters
9. Built-in CW keyer and memory keyer
10. Good sounding audio
11. Band-selected interface (for external band selected decoder)

I've used the Yaesu FT-847 for many years and was satisfied with it's operation so I went with the more compact and improved FT-857D.

FT-857D on-line references:

• Operating manual and download the pdf manual
• Service manual and download pdf manual
• KB2LJJ FT-857 Mods Database
• DXZone Ft-857 links

The ICOM 706MKIIG may also satisfy many of these criteria if this is your preference.

What I like least about the FT-857D:
I also discovered that the FT-857D had its share of "quirks" but most of these were overcome without too much difficulty:

1. DC current "spike" when the radio is first turned On.

2. RF power "spike" when PTT turns On (with lower power output levels) and limited delay (up to a max. of 40 ms) between PTT On and RF output. (Note RF spike of approx. 150% overshoot in screen captures below.)

20 ms delay (PTT-RF out) 1 Watt on 432 MHz

40 ms (PTT-RF out) 1 Watt on 432 MHz

 3. Minimum of 5 watts power output on all bands (unless you use the service menu settings or an external ALC voltage). 

4. Poor transceiver mode implementation (unusable in my case).


What I like most about the FT-857D:

1. Compact with remote head capability
2. Low noise cooling fan (when running)
3. Excellent noise limiter and DSP operation
4. Very quick to change modes, frequency and bands
5. CW AutoMode (menu#22) for automatic CW <=> SSB
6. Excellent audio with an external speaker (Cobra mdl. S300)

Mounting the remote, radio control head was accomplished using a 15" flexible gooseneck car mount kit from E-bay. It was easy to install with NO additional mounting holes required in my case.




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