| KG7M |
Rating:  |
2023-04-14 | |
| Older Examples Require Repairs |
Time Owned: 6 to 12 months. |
I picked up a FT-707 from the Estate of Hal Guretzky, K6DPZ. Hal had put one of his "Land, Air Communications" stickers on the rear of the heatsink. Hal is well known, and has 259 Reviews in the Amateur Radio Equipment Repairs section of these reviews. All Positive, until the last few. For many years he performed sterling work. Towards the end of Hal's life, the repairs became sketchy. May he rest in peace.
The FT-707 was in Hal's inventory at Land, Air Communications. A non-radio person had purchased a pallet of radios from the Estate. I purchased the FT-707 and a Drake 2B from this person through eBay. Prices were pretty reasonable as they were listed as Non-Working, Parts Only. Initially the FT-707 seemed to operate, but after a short period of time using it I discovered that it suffered from terribly distorted audio on both SSB and AM transmit. In addition, the VOX Circuit was inoperable during voice operation. It's a very early model using quite a few different transistors from those listed in the available Service Manuals.
I'm very grateful to the Review prior to mine, from David Burger, VK2CZ. Like David's, my Transceiver apparently was also modded by CBers. Hal had put it back to Amateur Radio use by replacing the 11 Meter Crystals with stock 10 Meter Crystals. His repair is pretty ugly, with lifted traces sloppily jumpered. Electrically functionaI though. I replaced about 30 Electrolytic Capacitors on the AF Board. A 1N270 had been soldered in place of the 1S1555 listed in the Service Manual on the AF Board as D01. I used a 1N914, a suitable replacement. Unusual, several of the listed 1S1555 Silicon Diodes had been replaced with 1N270s - a Germanium Diode. This could've been a Factory Mod as the soldering was done by hand, but quite well. The rest of the thruhole components were soldered by a Wave Solder Unit from the factory and not disturbed since. I replaced a J-310 FET and a 3SK73 Dual Gate MOSFET on the IF Board. These were Q07 and Q08 and are directly in the Transmit Audio/BM Chain. My Early Version used a Sony 2SK125 at Q07, not the listed J-310. Both are similar Low Noise, High Dynamic Range, UHF Amplifiers. I used a 2N4416 for the J-310 as I have a few of these left in my parts bin, and have had great success using them to replace obsolete JFETs in my Drake R-7 and TR-7. As for the MOSFET, the original 3SK73 is a Flat Package (HSTM) device, which I didn't have on hand. Instead I used a TO72 package 3N211. The replacement semiconductors function fine.
The defective VOX was due to a broken wire at the VOX GAIN potentiometer. Finally, the distorted transmit audio was due to a fried, and shorted Tantalum in the PA BIAS C13 - JUST LIKE THE PREVIOUS REVIEWERS FT-707. Yaesu used a 10uF/16V Tantalum. I replaced it with a 10uF/25V Tantalum. Oh, and my speaker is defective, just like the previous reviewers.
So the FT-707 is back up and working great. I'm pressing into Data Mode service, mostly FT8. Yes, the FT-707 can be drifty, I'll leave it on 24/7. The FT-707 can be used Fixed Frequency by the use of Quartz Crystals. There is an internal socket for each band. Perfect for using it on FT8. But crystals are impossible to come by nowadays. Last year I picked up a device called the Prog-Rock kit from QRP Labs in Turkey. It's really cool as it sports 9 Registers that can each hold 3 different frequencies. In reality, one shouldn't use more than one frequency per Register due to crosstalk. Each Register can be selected by either pulling one of the three control lines low, or leaving it high. The Prog-Rock programs the needed frequencies via a DIP Switch and push button. I've mounted a Prog-Rock in a small cabinet with a 9 Position Rotary Switch and 8 cables exiting and terminating in either an unused, empty crystal holder, or 2 Inline Header Pins, to plug into the Yaesu's Fixed Frequency Crystal Sockets. By depressing the FIX button on the FT-707's front panel, and selecting 80m - 10m on the Bandswitch, I can run any of the main FT8 frequencies for most of the HF Bands. Solves any drift! QRP Labs discontinued the Prog-Rock, but I spoke to Hans Summers, G0UPL - he's currently working on a new version that will be for sale in the future.
Hope I didn't offend anyone with the length of my review. I feel that it's extremely important that we share all of our knowledge, including detailed repairs. I'm 70 and won't be here forever. Once the older Hams are no more, the younger people may not have the time to spend troubleshooting. User Groups used to be the vehicle for our knowledge base, but most have shut down. I think we would be smart to share our findings right here.
UPDATE APRIL 2023:
During a great opening to most of the world, I ran 4 hours straight using FT8. I had the FT-707 pushed to the maximum when I smelled burning components. I lost all RF Power. Upon checking I found a burned up 18 Ohm resistor (R20), and a defective 7808 Voltage Regulator (Q06) on the 100 WATT PA BOARD. After the repairs the FT-707 is putting out only a couple of watts. I believe the Final RF Amp Transistors are blown. They are 2SC2290x2. Expensive and difficult to replace. I may opt to just bypass them and run the Drivers (2SC2395x2) as Finals. The Drivers are rated up to 30 Watts Output. So I figure a conservative 40 Watts Output from the pair. I will update my Review either way. |
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| VK2CZ |
Rating: |
2020-12-13 | |
| Remaking a great rig |
Time Owned: 3 to 6 months. |
Was fortunate to have two of these radios come my way for no cost, noting both were dead, and one had fallen foul of a non-professional workmanship operator (with a CB xtal fitted).
First up was fault find, very easy but mechanically awkward.. Here are the faults found:
- Shorted tantalum in PA bias.
- Open circuit speaker
- Bodgy ext speaker wiring (not factory)
- Broken +12v wire on rear of band switch (this is impossibility short and will break during dismantle without care)
- About 12 of the 98 electrolytic capacitors in each radio were leaky or near open circuit. All were visually physically perfect. Electrolytic's only have a 10 to 12 year life.. beyond that, they are rubbish..
- One wire had pulled out of its crimp plug on the Audio board..
With that done, the radios were near normal, but way off in alignment.. ie LSB / USB switching sounded nothing like each other, plus the dial lights were blown, and the LEDs were maybe 10% brightness.
The manual is excellent in the alignment process, barr ALC adjustment.
Made up a new 7 segment display board using blue LEDs with Eagle, and on version 3.. worked perfect! Hand made about 18 replacement 1mm x 5mm LED from blue, amber and red.. ditching the original orange and green livery of the factory.. Found a set of 2.1Khz INRAD SSB filters from Scott, and the radio was ALIVE !!! I moved the 2.9Khz SSB into the CW position.. (I'm not into CW)
This is not an economic task, just a tech challenge I set myself.. Sold the radio to Brenton Meadows who did a youtube review of it.. Google "Brenton Meadows FT707" for a squizz. Next challenge is my FT107M.. very similar.. watch my next review on that antique.. |
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| W0RDX |
Rating: |
2020-06-24 | |
| Great non menu radio |
Time Owned: more than 12 months. |
| Fun radio to use, simple to operate, no menus. For the sale price these days 300-400, a great investment in a radio perfect for camping, portable, mobile, base, you name it. |
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| IT9AHH |
Rating: |
2018-05-06 | |
| vy good rig |
Time Owned: 0 to 3 months. |
I have a 2nd hand early serial 0H ft 707 near mint conditions...virtually unused. My ft 707 comes from an Austrian seller. Excellent if noise blanker if width and vy low noise floor receiver.
This 707 delivers up to 150/160 watt on 3.5 mhz and circa 120 watt on 28 mhz.The rig was about 200/300 off frequency on cw...correcting the frequency readout on both rx and tx was a joke by adjusting the compensator on the counter unit pcb as per user manual.
If your 707 suffers from overheating follow the instructions of Nigel g4nrr on mods.dk and you will solve this issue.
After warm up i did not notice any frequency drifting ... even after hours the radio is stable and solid as a rock.
I love this old classic rig.....pay attention to the seller there are many heavly modded 707!!
73's
franco, it9ahh. |
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| F8WBD |
Rating: |
2015-09-07 | |
| Good general use rig |
Time Owned: 3 to 6 months. |
| QRP CW operator for many years and continue in that niche of the hobby. Have a number of 5 watt rigs. However, I wanted a QRO transceiver capable of higher power for periods when extended poor propagation was unfavorable at 5 watt levels. Essentially to keep my CW skills up when serious lack of activity a possibility. I picked up a third-hand FT-707 at a fair price recently. No QSK or CW filter unfortunately. But, it is drift free after a minute and the front-end is reasonably sensitive and selective for an elderly rig. Don't care for the horizontal bar meter but that is a minor detail. Delivers 100 watts but I never go above 50 or 60. I do not chase rare DX or expeditions and satisfied with Transatlantic contacts into the NA/CA/SA part of the world. The FT-707 delivers good, casual CW QSOs on 20M using a low EF-20 antenna. If you want a back-up QRO rig for those days when your little QRP transceiver can't deliver. you might consider the FT-707. Remember these older transceivers may not have replacement components. I would not sink a lot of money into any 30+ year old rig and I didn't. |
|
| G1HBE |
Rating: |
2015-07-12 | |
| A nice little rig! |
Time Owned: 0 to 3 months. |
| I pickrd this up for a very small outlay at a local rally. 'PA not working, other faults', said the sticker, but it looked so neat I decided to take a punt. The RX works fine and the recovered audio on SSB is a joy, so clean and smooth. The PA was fixed very easily - the bias supply to the transistors was missing due to a shorted diode. I want to improve the AM RX, it's rather narrow and 'thick' sounding. Trouble is, the AM bandwidth is governed by the PBT filter. More work required! BTW, I would NOT remove C66 to get more 'top', as it is part of the Zobel network that stops the audio chip frying itself! |
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| WP4OEK |
Rating: |
2013-12-08 | |
| Great radio |
Time Owned: 0 to 3 months. |
| Got one from ebay with FP-707. Great audio !! |
|
| N3TU |
Rating: |
2013-10-11 | |
| First Radio in 1992 |
Time Owned: more than 12 months. |
| That was my first radio back in 1992. Sold it around 1998 to upgrade my radios a few times. I miss that old radio and should have kept it. It was a great radio to learn the 20wpm cw requirement at the time. |
|
| MI3LVZ |
Rating: |
2013-08-23 | |
| A cracking little radio |
Time Owned: 0 to 3 months. |
I got mine off Ebay for little money. Came in fantastic condition for its age. A surprisingly very good receiver with excellent audio reports even with the standard mic. The VFO felt a bit notchy and ruff so a quick strip, clean and regrease sorted that, be careful when rebuilding the slowmotion drive as its a bit of a bugger!!
Great for some portable opps or even as a back up rig. Who really needs all the bells and whistles of the modern rigs when cheap and cheerful is all you really need.. |
|
| SV9DRU |
Rating: |
2013-01-24 | |
| Audio mod ! |
Time Owned: 6 to 12 months. |
Very good analog design with extremely clean TX/RX due to its lack of PLL sinthesizer. Every band coverage is derived from mixing the analog VFO signal with a crystal oscillator signal. You can't get much cleaner than that phase noise wise.
It is true that as any other more than 30year old radio, it will most probably require some TLC to bring it to its full potential, but that is part of the hobby isn't it ?
At any rate, after giving that TLC to mine, I was rewarded with a beautiful RX, but rather bassy audio response. The same is not the case with my FT-901 and 902 rigs which also have solid state AF stages.
The secret to bringing the FT-707 up to its big brother's potential is simply removing C66 from the AF board, a 0.1uF cap bypassing the audio signal to ground via a 1 Ohm resistor, just before reaching the speaker.
This 10min mod will make the signals sound much more natural in AF high frequency response, without increasing the hiss or making the rig any less "quiet".
By the way, the FT-707 is one of the rigs that when you remove the antenna while listening at a comfortable audio level, the RX goes almost completely dead !
It very much rivals my Drake TR4 despite it not having magic glowing bugs inside hi
73 to all,and keep those soldering irons hot !
Marinos |
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