The FT-817 Page

The FT-817 is Yaesu's unique, tiny, MF - UHF low power amateur radio transceiver. On this page I've posted notes on various things related to it which may be of interest to fellow users. If you're interested in more information about using the FT-817, however, I'd recommend joining the FT-817 group at Yahoo. This group has an FAQ which is worth reading if you're a new or prospective FT-817 owner. It contains answers to most of the questions you may wish to know.


Thoughts on the FT-817

Many reviews of the FT-817 have been published on the Web, and in magazines like QST and RadCom. I'm not going to add another. Instead, I'll just list what I think are the good and bad points of this radio.

picGood points

  • Small size. This is probably the FT-817's most important attribute. There's nothing smaller, apart from FM-only HT's and one-or-two band QRP CW-only radios. It's small enough that you can slip it in your rucksack or even a pocket just in case you feel like having a few QSOs while you're out. This is something you wouldn't be tempted to do with the Elecraft K2 (which I also own.)
  • "All-band" coverage. The FT-817 covers all amateur bands from Top Band to 70cm (excluding the UK-only 4m band and the US-only 222MHz band.) It also has pretty extensive general coverage capabilities. This makes it an ideal "do-anything" radio, suitable for whatever kind of operation you feel like doing.

Bad points

  • High power consumption. The FT-817 consumes around 400mA even on receive. This is pretty poor, especially given the limited capacity of the battery pack (see below). Yaesu could surely do better. The Elecraft K2 draws about 240mA on receive, normally configured, but this can be reduced to about 140mA for portable use by invoking various power-saving options.
  • Low battery capacity. Eight AA-size cells are too weedy. The original factory-supplied rechargeable NiCd pack had a capacity of just 1,000mAH. The current FT-817ND model has a NiMH pack with 1,400mAH capacity. This is barely enough for three and a half hours of listening, with no transmitting. Yaesu should either have increased the size of the radio to permit a bigger battery pack to be used, or offered a Lithium-Ion battery option (as used as standard in the VX-5R) to permit greater capacity in a small size. This would also allow 5W to be used when running from battery power.
  • Only 2.5W on battery power. The FT-817 is advertised as a 5W radio. But on battery power the maximum output power is normally 2.5W. This can be overridden, but bearing in mind the limited battery capacity this may not be a good idea. But it's disappointing. Let's face it, out portable you are probably going to be using a pretty inefficient antenna, so being limited to 2.5W as well isn't going to help.
  • Poor receiver. A contest-grade receiver isn't expected nor required in a radio of this type, but the FT-817's receiver seems poorer than it need be. Even using an inefficient short whip, strong local stations can overload it. The main problem seems to be bleedover (apologies for the CB term, but it sounds just like a cheap CB radio) due to the inadequate IF filter fitted. A better filter is available as a (pretty expensive) option, but you can only fit one accessory filter, which is a problem if you want a narrow filter for CW.
  • No ATU. The FT-817 has no internal ATU. Originally I thought that this was a reasonable design compromise. However, having experienced how hard it is to get small portable antennas to match in the varying environments in which they may be used, I began to realize that an ATU would be very desirable. Most ATUs are the size of the FT-817 or larger, which negates a lot of the benefits of the radio's small size. However, Elecraft has recently introduced a tiny portable QRP auto-ATU, the T1. Read my review of it.
  • Poor ergonomics. Many commonly used functions are accessed from one of the three buttons below the display, which have about 11 different sets of functions. This means a lot of button pressing and knob twiddling just to do something like turn the noise blanker on or off, change the output power or toggle the meter between SWR and power out. Although to a great extent this problem is inevitable given the small size of the 817's front panel, I'm sure Yaesu could have fitted a slightly bigger LCD panel, with less of a surround, and this could at least allow the current selection of the three buttons to be permanently displayed. Perhaps some functions could have been made accessible from a key-pad mike, as well? Direct frequency input would have been nice.

The bad points outnumber the good points. Whilst some allowance must be made for the FT-817's small size and portability, especially with regard to ergonomics, several of these criticisms could have been averted using existing technology.

Overall I give Yaesu only 7 out of 10 for this radio, with the comment "could do better." But there's nothing else quite like it on the market at the moment. If you want a very small all mode HF and VHF radio, better get an FT-817!



Several small portable antennas are now available which allow you to easily get the FT-817 on the air out in the field. In my search for the ultimate portable antenna I have tried the Superantennas MP-1, the ATX Walkabout and the Miracle Whip.

However, a piece of wire will always give better results than a short whip (if it is longer than the whip, obviously!) Elecraft's T1 portable automatic ATU, with optional FT-817 interface cable, is the ultimate FT-817 accessory. It's the size of a pack of playing cards, it's powered from its own internal PP3 battery, and it turns a couple of lengths of thin wire into a really effective portable antenna. Read my review of it.

SWR foldback

One of the problems with operating portable is that different environments can affect the performance of small whip antennas. This means that settings which gave a good SWR in one location may not be reproduced in another. If you use a short feeder, losses in the cable due to a high SWR will be minimal. However, if the transceiver backs off the power when a high SWR is sensed, you may be radiating a poorer signal than you expected. I therefore decided that I should check what the FT-817 does when faced with a poor SWR.

The good news is that when operating on the 2.5W mode (the default for battery power) the FT-817 appears to deliver the full 2.5W regardless of SWR. I guess this applies to the lower power modes too.

In 5W mode, however, there is some SWR foldback. Full power is delivered as up to three bars of the built-in SWR meter are displayed. When the fourth bar appears, power is immediately reduced by about 20%. When the fifth bar appears, power is reduced by about half. Therefore, when running 5 watts, it is important to ensure that the SWR seen by the FT-817 equates to three bars or less. This is equivalent to around 2:1 or more, so the radio is really quite tolerant of SWR mismatches.

Working SSB

It is possible to work SSB DX using a barefoot FT-817, even with modest antennas. However, it certainly helps to pay attention to your transmitted audio, to maximize your chances of being copied when you are down in the noise or competing with higher-powered QRM. A speech processor will give your SSB signal valuable extra "punch".

One possibility is an audio processor such as the "One BIG Punch" from W4RT. I haven't tried it, and it's not an option I would choose. Audio processing can actually end up making your speech less intelligible, because it produces in-band distortion products. Put simply, if you clip a 400Hz signal, it creates harmonics at 800Hz, 1200Hz and so-on.

RF Speech Processor

RF speech processing avoids this issue by converting the audio to an RF double-sideband signal before clipping or compression. Any harmonics produced will be harmonics of the RF frequency used. If the RF processor uses 455KHz then the harmonics would be 910kHz, 1365kHz etc. which are easily filtered out using a narrow band filter. The RF is then demodulated back to audio again. This gives a cleaner sounding signal for the same amount of compression.

Joachim, DF4ZS makes an RF processor board that can be installed inside the FT-817 microphone. It costs about 65 Euro. You can either fit it yourself or send your mike to Germany with return postage and Joachim will fit it for you.

The processor replaces the standard microphone element with an electret type that has more of a treble emphasis. This may not suit all voices but it can enhance copy under difficult conditions, compared to the normal Yaesu rather muffled audio. I think it sounds excellent on FM, too.

You can see the difference here in these two oscillograms.

The difference doesn't look that great. That's partly because the AGC in the receiver used to make the recording has brought the signals up to a similar level. But you can see that there is less difference between peaks and minimums in the compressed oscillogram. Each syllable looks (and sounds) clearer.

To see what the difference sounds like, you can listen to the recordings.

This is not a strictly fair comparison, because I did not make a recording before the FT-817 microphone was modified. I think even the uncompressed audio using the electret mike is an improvement over the original. Again, there isn't a huge difference in loudness between compressor on and compressor off, due to the AGC effect. The compressed version sounds compressed, and the uncompressed audio is certainly more hi-fi.

What is not apparent from this is that the compressed transmission is narrower and cleaner. That's because without the compressor, the FT-817's ALC is providing the compression. I have done what most FT-817 owners probably do, and turned the SSB mike level up to get a louder signal, at the cost of a bit of splatter. The RF compressor cleanly reduces the peaks, as well as bringing the lower levels up, so the ALC doesn't have to work so hard. The end result is a louder but cleaner signal. Whether that's worth the cost is your decision.

Working CW

To get the most out of your FT-817 you need to use CW. There is no argument about it, especially at the current point in the sunspot cycle. Low power + SSB + a poor antenna + poor conditions = frustration. Low power + CW + a poor antenna + poor conditions = the thrill of making contacts over thousands of miles under far from optimal conditions. SSB needs a much bigger signal to noise ratio than CW to be read, plus it needs a wider bandwidth receiver, which increases the amount of noise the listener has to contend with, decreasing their chances of being able to hear you. You need about 100W of SSB to be heard as well as 5W of CW, so using the code will boost the number of contacts you can make considerably.

This might not be what you want to hear, if you are not a fan of CW. But in my experience people who are not CW fans don't like the mode because they find it too difficult to use - because they didn't learn it properly. For years I resented the need to learn CW and never used it after I passed the test - until I got interested in QRP and realized the benefits of it. Becoming competent at CW can be hard, but it really repays the effort. If you aren't there yet, I have a couple of programs that will help you get your speed up. MorseGen is the ideal code practice generator, while if you want learning to be a bit more fun, to give you more incentive to practice regularly try MorseTest.

CW filter

To use CW with the FT-817 you need to install the optional CW filter. The standard filter is too wide, so you hear too many other signals and noise, making it hard to copy any other than the strongest signal in the passband.

The Yaesu YF-122C CW filter is quite an expensive option, especially here in the UK. However, I found a very reasonably priced alternative. Jim Wiggenhorn, K8DRN, is selling a Collins mechanical CW filter for the FT-817 for $89. Shipping to the UK is a further $7 (that's about £50 in total at the current conversion rate - eat your hearts out Waters and Stanton.) Contact K8DRN (at) for more information. In theory, buyers in Europe could have to pay VAT plus a collection fee to the Post Office, but small items like this usually slip through without being charged, and no-one I know of has had to pay this. Even if you do, it still works out cheaper than buying from a UK dealer.

This filter is exactly the same as the one supplied by Yaesu, except that the blue label on the top says Collins instead of Yaesu. Dave Fifield, AD6A, has published some excellent instructions for installing a CW filter in the FT-817.

Morse key

To use CW with the FT-817, you'll also need a Morse key. Even if you already have one, it's probably a chunky model made for sitting on a pic desk, with a heavy base so that it doesn't move around when you use it - not the kind of thing you want to have to lug around in a backpack when you go portable.

I had been on the lookout for a really small Morse key for a long time, but the only ones I found that were small in size were not small in price. However, I recently found run by Lou, K9LU. There, you will find some very nice, small Iambic Morse keys at very reasonable prices. There is one that fits to the carrying strap bracket of the FT-817 and costs just $27.95. I purchased the Bulldog BD2 Mini-Key at $32.95, which has a small magnetic base. It comes with a metal washer you can Blu-Tack to the desk to provide a strong mount. However, the strong magnet will also stick to the top cover of the FT-817 or another small portable radio. Just use a piece of thin felt or thick paper under the base of the key, to avoid scratching the paint.

These very small keys are not as adjustable as the larger, more solid keys, and my only complaint is the touch is a bit light. But for the size (and price) they are excellent. The BD2 comes in a strong plastic canister (like a 35mm film canister, but larger) which is the perfect container for carrying the key around safely in a backpack.

Computer control

I am not going to write very much about computer control (CAT) software for the FT-817. Computer control is not something I personally have much of a use for with this radio, as for me the 817 is a portable radio not one to be used on a desk near the computer. However, I did use computer control when I used the radio briefly with the wxtoimg software to receive weather satellite images. The computer control enabled the software to track the doppler shift, which greatly improved the quality of the received audio, which is too wide to be received comfortably through the FT-817's narrow FM filter.

You can pay a lot of money for a CAT cable for the FT-817. I bought mine on eBay for about 10 Euro from a German ham who makes them. His call is DG5BE. He doesn't appear to have a website, so if you can't find his adverts on eBay you could try sending him an email: his address is dg5be at gmx dot de.

The most comprehensive computer control program for the FT-817 is FT-817 Commander. This program is the predecessor to Ham Radio Deluxe, but it has many features specific to the FT-817, such as memory management, which HRD does not. Although FT-817 Commander is unsupported, and does not claim to support the FT-817ND, it appears to work, although I have not used it a lot.

If you just need a program to help you manage the memories in the FT-817, then I suggest that you try 817-Mem, written by F5BUD.

A portable power supply

My FT-817 sits quite happily on top of my Maplin 3A power supply and looks as if it was made for it. Unfortunately, the magnetic field from the mains transformer affects the 817's VFO, giving a "dirty" note to signals. The power supply is also twice as high and about 4 times as heavy as the FT-817, making it not something you really want to carry around on trips. I thought I would try to find something smaller and lighter.

Previous experiences with switched mode power supplies have led me to regard these devices as the work of the devil. Nevertheless, no analogue supply capable of delivering at least 2A at 12V was going to meet my requirements. I obtained a 12V 2.5A switched mode PSU from Maplin Electronics, order code GS83E. This is like a laptop computer power supply, dimensions 140 x 60 x 40mm. It comes with a standard coaxial power jack, suitable for the Elecraft K2, so for the FT-817 I also ordered a power adapter lead (AQ81C) and tip (AR22Y).

The PSU lived up to my worst fears. Connected to the K2, load broadband hash covered every band, drowning out every signal. The hash appeared to be picked up by the indoor antenna. The power cable from the PSU is coaxial, with the negative the braid. However, there appears to be no connection between the braid and mains earth. Grounding the radio to a suitable earth such as a radiator made a big improvement, but the hash was still intolerable. As I'm not happy messing with mains voltages, I didn't try modifying the PSU to connect the DC negative side to mains earth.

A remedy was found when splicing on the adapter for the FT-817 power plug. Close to the plug, as many turns as possible of the thin twin-flex adapter lead were tightly wound onto a ferrite core as used for curing breakthrough problems. The turns were taped tightly to hold them in position. The excess lead was cut off and spliced to the coaxial power cable from the switched mode PSU.

The power supply is now usable. Some hash is still noticeable, but it is not strong enough to drown out any station who is strong enough to indicate he has a chance of hearing my 5W signals. Of course, your chances of making QRP - QRP contacts with this power supply are reduced, as you may not hear the other guy.

Note that this hash is only discernible using an indoor antenna such as the ATX mounted on the back of the rig. Using an outside antenna with a feed point away from the shack, you would not know you were using a switched mode PSU. This is still disappointing, though, as one of the main uses of a small, lightweight PSU would be to power the radio in /A locations (hotel rooms, etc) when the chances are you will be using an indoor antenna.

Battery charging issues

One question that sprang to mind after getting the 12V switched mode PSU was: would using a 12V supply affect the battery charging function of the FT-817? Would the batteries need to be charged for longer? Would the voltage be sufficient to charge the batteries at all?

The answer is that there is no problem. In normal use, when connected to a supply, the internal batteries are trickle charged with a current of 25mA. In charge mode, a constant current of about 190mA is used. With the switched-mode PSU, the FT-817 reads the supply voltage as 12.2 or 12.3V. There is a barely discernible increase in both trickle charge and full charge currents (a milliamp or two) as the input voltage is brought up to 13.8V. This is not enough to matter. The charging current drops off quite steeply as the supply voltage drops below this level, however, so you should not expect to fully charge the batteries with the 817 connected to a supply of less than 12V.

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