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Yaesu FT-707

The Yaesu FT-707 is an analogue HF transceiver, with which I have a special connection and which is one of my restoration projects. Below you can read how I got acquainted with this set and how my restoration project is going.

Don't feel like reading my whole story? Via the links in the menu you can jump directly to the chapters with technical restoration information.

Back in time

When I got my full licence in the eighties, in the Netherlands called the A licence, I was allowed to use shortwave as a ham. I did not yet own a HF shortwave transceiver and was more than intrigued when I got the tip that someone in a nearby village had a HF transceiver for sale.

I went to have a look and found a nice working Yaesu FT-707, including FC-707 antenna tuner and YM-35 hand microphone. The set appeared to be converted and used for the 27M. The four 10 meter crystals had been replaced with 11 meter crystals. If I were to buy the set, I would get the original crystals with it. The seller, however, wanted the four 11-metre crystals back. After I had checked the operation of the set, the sale was quickly concluded and I was the proud owner of my first HF transceiver.

Yaesu FT-707 specifications

For that time, this was a nice modern and compact HF set with all HF bands between 10 and 80 meters including e WARC bands and the modes LSB, USB, AM and CW. My set was also equipped with the optional CW narrow filter.

The FT-707 is a fully analog design set, equipped with a VFO with a range of 500 kHz. That is wide enough for all HF amateur radio bands except the 2 MHz wide 10 meter band. This is divided into four parts of 500 kHz, marked on the band switch as 10A to 10D. Hence the four 10 meter crystals, which were replaced in my set for 11 meter crystals.

For accurate frequency reading, the FT-707 has a built-in digital frequency counter. Handy, but not indispensable. The set also features a beautifully illuminated analogue tuning scale and a marker generator, which allows the outer ring of the large VFO knob to be set to the nearest kHz.

The FT-707 was designed in the early 1980s and is suitable for both mobile and stationary use.

Two versions are available. The FT-707 with a 100W balanced transistor output stage and the FT-707S QRP version with a 10W balanced output stage. The output stage is mounted on the back of both models. The 100 Watt output stage is equipped with a large heatsink with built-in fan and therefore protrudes quite a bit. The 10 watt output stage is less deep and has no fan, so it does not protrude.

First test

When I got home, I first put the set together to admire the complex analogue construction and replace the four 11-metre crystals with the original four 20-metre crystals.

The seller wanted to keep his power supply, which was also not an original Yaesu power supply. This was no problem for me, as I already had a nice heavy 25 amp Philips power supply to test the set on.

The FC-707 antenna tuner has a built-in dummy load and after I had set everything up properly, I came to test the set. Everything worked fine and with 100 watts output power, the dummy load warmed up quickly.

HF antenna

Of course, I also needed a HF antenna. After some research, I chose an inverted-V dipole that I could string from the side of my parents' house to the edge of the front and backyard.

The local installer, who had also assembled the tube for my 2m Yagi antenna, was called in to mount a pulley at the top of the tube. This way I could easily hoist my HF dipole upwards. The bottom of the tube was near my bedroom, aka shack, so the antenna cables could be kept short. Now the inverted-V dipole still had to be connected.

The FC-707 antenna tuner has an asymmetrical coax output. This gave me the idea to equip the inverted-V with a Colins air balun and feed the antenna with coax cable. A construction that worked well for many years without any problems.

If you have worked for years on 2 meters with 10 Wat, 100 Watt HF seems a lot, but I soon found out that this is not so bad. With 100 Wat I could join in nicely on HF. Regularly I made Sunday afternoon contacts with the 'runaway' Dutchmen in the US after the morning church service with a cup of coffee, moved to the shack, aimed their big beams at the Netherlands to make contact with a good kilowatt of HF power to the motherland :-).

After many years of inactivity, I decided to sell my first Yaesu FT-707 including tuner at the end of the eighties and the beginning of the nineties. I was wise enough to keep my heavy 25 amp Philips power supply.

Back to the present

Wanted and found, Yaesu vintage HF transceiver, antenna tuner and desktop microphone from the eighties

FT-707 transceiver wanted

After I became an active ham again in 2021, I started to long for the analogue simplicity of an FT-707. So I started to look around on the second-hand market to see what was on offer. It turned out that more people were interested in this beautiful vintage equipment and several times, I saw a good working Yaesu FT-707 changing hands for an amount well above my budget.

Eventually, I came across two affordable defective ones whose output stage had blown up. A 100 Watt FT-707 and a 10 Watt FT-707S that I could take over for a nice price. For little money, I bought two nice restoration projects. A few months later, I came across another FT-707 with the same defect. I was able to exchange it for a two-meter that I bought second-hand but didn't like. With a restoration project, it's always handy to have an extra copy, so you can exchange defective parts or whole units.

FC-707 antenna tuner wanted

Then it was time to search for the FC-707 antenna tuner. Because of the long range and small size of the FC-707 antenna tuner, this is still a popular tuner and I saw bids on these tuners getting high as well.

Nevertheless, I managed to buy two of them for a reasonable price. The first one was the bare tuner without case and without the built-in SWR meter, but with the built-in dummy load. The second one was a complete FC-707 tuner in good condition. The complete tuner without case, the first one, I built in a suitable metal case, which my brother PG0V still had in the attic and this tuner is now in his shack. The second complete FC-707 I use to tune my own HF wire antenna.

YM-38 table mic and YM-35 hand mic wanted

My first FT-707 was equipped with the YM-35, a nice rugged handheld microphone. On HF, I found a handheld microphone less convenient when logging calls, which was still an obligation in the eighties. Yaesu sold the for that time beautiful and modern YM-38 table microphone, which I bought new and later sold together with my first FT-707.

After I bought the FT-707 transceiver and FC-707 tuner, I couldn't help but look for the YM-38 table microphone and the YM-35 handheld microphone. I have not been able to find the YM-35 handheld microphone yet, but I did find a somewhat battered YM-38 table microphone for a reasonable price.

The previous owner had tried to provide the microphone with adjustable preamp. For this purpose, a hole was drilled in the base for a potentiometer. After I marvelled at the attempt to provide a low impedance microphone with a high impedance preamplifier, I removed it. The original impedance transformer with which the 600 Ohm microphone could also be connected to a high impedance input, was unfortunately beyond rescue and I also removed it. The FT-707 and many other Yaesu transceivers have a low impedance 600 Ohm microphone input, so this transformer is not needed either. Because I don't have a cover for the input wire, I left the potentiometer in place.

I have not found the YM-35 microphone yet. Do you have a Yaesu YM-35 microphone lying around that you want to get rid of? Please let me know.

en/projects/yaesu_ft-707/start.txt · Last modified: 2023/07/09 01:34 by bart

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