The Yaesu FT-857 is the mobile version of Yaesu's ubiquitous FT-897 transceiver. Yaesu designed the 857 with size in mind and claims it is the most compact 100 watt HF/VHF/UHF transceiver on the market today. It is certainly suitable for mobile operation, but can also be quite usable for portable or even occasional desktop use.
The current version of the FT-857 is designated as the FT-857D. The main enhancement of the 'D' model is the inclusion of the five 60 meter frequencies available to US amateurs. These may be accessed via a special pre-initialized memory bank. Where I refer to the FT-857 below, it applies to all members of the FT-857 family, including both the 'D' and non-'D' versions.
Because of the similarities between the FT-857 and FT-897, if you are familiar with one of these rigs, it is a simple matter to convert to using the other. I acquired an FT-897 in the fall of 2010 and used it often throughout the winter. In April 2011, I reviewed it. Then, in the spring of 2011 I was offered a slightly broken FT-857 for a very good price. The unit was sent to Yaesu for repairs and has been employed as a secondary rig in my hamshack for the past several months. Many of my comments in the FT-897 review are applicable to the FT-857 as well. Rather than re-hash them again here, I invite you to read my review of the FT-897. I'll point out the pertinent differences between these two siblings below.
The FT-857 shares its electronics and firmware with the FT-897. The main difference is the packaging. The FT-897 is a physically larger rig, with space internally for adding either an optional built-in power supply, or two battery packs for portable operation. It also has an additional knob on its front panel and the 'D' version of the FT-897 comes from the factory with a temperature controlled crystal oscillator (TCXO) installed, as opposed to the standard XO found on the FT-857.
Although these Yaesu siblings have similar controls, that's not to say the two are interchangeable. I view the FT-857 as predominantly a mobile rig which requires a 13.8VDC power source. The FT-897 is a portable rig with can be optioned for 13.8VDC, 120VAC, or battery power. In my mind, neither is ideal for a desktop rig. The I initially viewed the FT-857's small size as a detriment and until I acquired one I would never have believed I would come to prefer the FT-857 over the FT-897 in several respects.
Other differences between the FT-857 and FT-897:
There is not a lot of real-estate on the front of the FT-857 and Yaesu must have spent considerable time laying out the front panel to be efficient without being cramped. And, they've largely succeeded: Even with its small form factor, it's a remarkably comfortable rig to operate. The controls are logically placed and easy to access and manipulate. All the controls are lighted so they can be easily located in the dark or with only a quick glance. Many are situated around the perimeter of the front panel, giving each button its own unique location or tactile feel. This further enhances accessibility. For some reason, this physical layout is easy to learn and soon seems as natural than the more conventional front-panel of the FT-897, at least to me.
The display on both rigs is relatively small, with the FT-857's being the tinier of the two. However, it is well laid out, and I don't miss the extra real-estate on the FT-897's display. It also seems the sharper of the two and has greater color purity, but that might only apply to my units. The main effect of the downsizing is to replace the rather prominent bar-graph meter on the FT-897, with a smaller version on the side of the 857's display. While this makes it more difficult to discern precise values, such as S-meter readings, it's still quite easy to make relative assessments and is good enough for most purposes.
An unfortunate compromise in the design of the FT-857 places the microphone jack behind the front panel plate, making it is necessary to remove the front panel to change microphones. The arrangement makes sense in a mobile environment, where one would tend to use one of the standard Yaesu handheld mics exclusively. And, realistically, this design probably makes the mic connector more secure. However, when used as a portable rig, you'd probably want to unplug the mic before packing and transporting the rig, something which becomes a bit more involved on the FT-857. It also makes fabricating an interface for a non-standard microphone a bit of a challenge, since any cable termination would have to take into account the close fit behind the faceplate and have a round cord capable of making a sharp 90° bend to exit the rig. Perhaps Yaesu should offer a 2" male-to-female RJ-45 mic extension cable for the rig, just for this scenario.
The positive side of the removable face plate is that, with the optional YSK-857 separation kit, the front-panel/head of the rig can also be remotely mounted on the dash, allowing the bulk of the rig to be stored out of sight wherever it is convenient — another nod to mobile operations.
The back of the rig has two SO-239's (one for HF/6m and the other for VHF/UHF), both solidly attached to the heat-sink/frame. However, the power connector is on a pigtail. Interestingly, there is a small brown wire going to a spare contact on the power plug. Inspecting the schematic reveals that grounding this wire makes the FT-857 behave like the FT-897 when the latter is being powered from battery packs — it causes the max power to be set back to 20 watts and makes the display back-light non-continuous, and probably does a few other things, too. The rest of the receptacles on the back of the FT-857 are identical to those on the FT-897.
Due to its size, the FT-857 necessarily has a physically smaller heat sink. Like its big brother, it has dual fans which turn on each time the rig goes into transmit, and stay on if the heat sink temperature rises above a nominal value. Because the fans and heat sink are physically smaller, the rig does tend to get warmer than the FT-897 in extended operation, although the fans do their job efficiently, and it never gets excessively hot.
The FT-857 retails for about $170 less than the FT-897. Most of this is due to Yaesu's decision to make a TCXO (temperature controlled crystal oscillator) standard on the FT-897, but a $100 option for the FT-857. Without it, the rig does drift some. This is especially noticeable when involved in 2m and 70cm sideband operation, where any XO instability will be most noticeable, and the digital modes, where frequency stability is important.
My biggest beef: The FT-857 does not have a manual notch filter, relying instead on a DSP-driven auto-notch filter. However, to be frank, the auto-notch simply doesn't do its job, leaving the user with no good option for suppressing carriers within the passband.
Like its big brother, the FT-857 gives you a lot of rig for the ~$800 it will cost to acquire one new. It's a handy little rig which does just about everything, although not all things well. Unfortunately, recent FT-857s and FT-897s seem to have a reliability problem involving the AM filter. It's a good choice for mobile operations and a reasonable one for a backup or portable rig, but I'd look elsewhere for a primary desktop transceiver for the hamshack. If you'd like to follow the scuttlebutt on the FT-857, I'd suggest joining the FT-857 Yahoogroup.