Opinions on the FT-857D

[VK5IR]

Hi all

Considering the purchase of a Yaesu FT-857D.

Would be used mainly for chatting on the local repeaters during drive time as well as mobile HF (with hopes of plenty of DX [emoji14]).

I'm keen to hear opinions from past and present 857D owners.

Thanks.

Sent from my SM-N910G using Tapatalk

[VK2AMS]

no complaints from me been a great radio, I have it as a portable rig all bands and also use it for repeaters, never had a problem ! touch wood ( murphy bugga off) !!! cheers
mark VK2AMS

[VK2SL]

I've had one in a 4wd mobile situation since 2004. It has performed flawlessly in all that time although in the last few months has developed a display problem which causes some lcd segments to fail. This problem has been discussed here on the Logger and there is a fix.
All in all a rugged bit of kit and a very good performer.
73
De Steve

[VK4JAM]

I have also had and 857D in a 4wd mobile situation (Pajero NL) since 2005. Similarly it has performed flawlessly - no display issues.
I use a panel extension kit, with the main radio boy located under the driver's seat. A brilliant radio!!!
73
Andrew
VK4JAM

[VK3TU]

I bought one of these radios when I went to Samoa in 2007. It hasn't missed a beat since. I have no idea how it works on FM because I never use it for that mode, I mostly use it for HF mobile and on V/UHF field days.

The RX slow AGC was still too fast for my liking and it had a tendency to "pump' on strong signals. I fixed this by adding a 1uF tantalum capacitor on the slow AGC line.

Another problem is I've never heard one that hasn't got some high frequency distortion in the RX audio. This is because Yaesu omitted to apply some negative feedback to the output stage above the filter cutoff frequency which means there's a pile of high frequency noise added to the audio which tends to distort the recovered signal. This is easily fixed with the addition of a simple RC circuit on the audio output IC.

The first issue is straightforward enough, just refer to the circuit diagram to find out where you need to add the C and the second is well documented here: <http://ok1fig.nagano.cz/>. Both are easy fixes and work well.

Yet another issue is the rather dismal front end noise figure on V/UHF. Something in the order of 7.5dB on 2m and 70cm. This Is readily addressed with masthead preamps at the antenna feed point but you do need to do some external work for DC feed and keying the preamps.

One annoying feature rather than a problem is that the radio works on HF, 6m, 2m and 70cm on all modes but only has 2 antenna connectors. That means you spend a lot of time around the back swapping antennas if you want to fully exploit the radio's capabilities. That's why I built an external antenna switcher that runs off the radio's band data available at the CAT/Linear accessory connector on the back (see AR Magazine, May 2015 for details). I just change bands on the radio and the antennas follow me to whatever band I pick. It also does the preamplifier switching and DC feed.

Another thing to consider is the current consumption on standby/receive. The 857 uses about 450mA while its Icom equivalent (IC706MkIIG) runs at around three times that and most of it comes out as heat. This is something to contemplate if you intend using the radio on battery power when operating portable.

Finally, care needs to be taken if you want to use the radio with an external amplifier for 2m or 70cm. The output level control is derived from the ALC line which means there is no control until the radio starts to make power. The issue here is that the output power spikes to about two or three times the rated power on the first syllable you utter. If your external amplifiers can't handle this sort of peak power at their input, then they're likely to suffer some damage.

I haven't had any display issues (yet) but like all LCD displays that use flex-film connectors directly bonded to the substrate, I expect it to fail one day. It might be possible to fix them otherwise one can always relegate it to the shack and run it with Omnirig and virtual display on a laptop with VKCL

Other than that, an excellent radio with intuitive menus and useful features that works a treat once you "fettle" it a bit.

Bert
VK3TU

[VK5IR]

Another problem is I've never heard one that hasn't got some high frequency distortion in the RX audio. This is because Yaesu omitted to apply some negative feedback to the output stage above the filter cutoff frequency which means there's a pile of high frequency noise added to the audio which tends to distort the recovered signal. This is easily fixed with the addition of a simple RC circuit on the audio output IC.

Mine's just developed the issue demonstrated in the video below. Crackling on RX. Research done online as well as advice given from Guy at JNB Electronics in Melbourne suggests the crystal filters suffer from corrosion and need replacing. The filters are $16.50 a pop and there are three of them to replace.

Has anyone done this job themselves?

[ZL3RC]

Havent replaced the filters in a 857 but have in a 897 and its relatively easy if you take your time.
My 897D just started to get noisy and it took a while before I realised what was happening and by that stage it was really bad!

I found the easiest way to get the old ones out was to break them up and then desolder and remove the bits, small metal plates.
The plates had a spring clip behind them and on all my filters there was a small amount of green corrosion build up which was i guess the problem.
Remember to do the bypass mod that removes the DC off of these filters otherwise they may do it again.
keep a track of which filter comes out of what position as the ones you have to replace them may have a slightly different part number

Good iron, solder wick and don't rush it you'll be fine. Just don't get to carried away with the heat otherwise you'll lift the very small tracks off the PCB and then you do have problems.

Good luck

Roger ZL3RC

[VK4BG]

Not only the filters...both the 857 and the 897 ( basically the same thing in a bigger box ) are exhibiting the same fault in that they will not power up. It is a design weakness in the power on circuit, where several SMC diodes can fail probably due to a current surge at the point of switch on. It is difficult to fix due to component location and access.

73
Glenn
VK4BG

[VK3TU]

...both the 857 and the 897 ( basically the same thing in a bigger box ) are exhibiting the same fault in that they will not power up. It is a design weakness in the power on circuit, where several SMC diodes can fail probably due to a current surge at the point of switch on.

Yep. They do like their start-up current. You need a pretty good low impedance power supply to fire these radios up.

Re the filters, that's something I omitted to mention because I haven't got around to modifying mine yet. There is plenty of info around on the web regarding this problem. The main problem isn't corrosion per se, it's that the DC bias applied to the filters because Yaesu were too stingy to put in some coupling capacitors. It promotes the growth of dendrites from the silver plated elements on the filter substrate inside the filters and they eventually fail.

Bert
VK3TU

[VK3ZAZ]

http://www.eham.net/reviews/detail/3046

No 2M preamp?
What were they thinking?

[VK3TU]

2m and 70cm preamps work best a the antenna, not inside your radio so leaving them out is fair enough but not providing a phantom DC feed to run one that can be selected from the front of the radio is gross omission on a radio purporting to be a VHF/UHF narrow band radio, I agree.

Bert
VK3TU

[VK3ALB]

Hi Bert,

This switch box will work with this set allowing you to switch preamps for 2m / 70cm and well as controlling amplifiers. An excellent project for anyone that has a FT857/897 or even 991.

[VK6ZFG]

Yaseu is not the only manufacturer to have had the ceramic filter problem.

I had to replace the ceramic filter in my Kenwood TS2000.