Yaesu FT-200, FT-250 & Tempo One

The FT-200 and low-power FT-200S were sold in Japan. The same design reached Australia and Europe; Sommerkamp marketed it in Europe as the FT-250. In the United States, Henry Radio of Los Angeles sold it as the Tempo One in white and black finishes.

Even after decades of service, these rigs remain distinctive on the bench and on the air.

Even as old as she may be, she’s still a pretty face!

Henry Radio also sold a remote VFO — the VF/One — which can be difficult to find. One lucky eBay purchase required buying the whole rig to obtain the VFO; with a little care it cleaned up as good as new.

Mobile Operation

How about taking your Tempo One mobile? An inside peek at the DC/1A DC-DC power converter:

Accessories for the FT-200 / FT-250 included the Yaesu DC-200 mobile 12 VDC power supply and the FV-200 remote VFO.

Henry Radio’s Tempo VF/One remote VFO — an eBay special cleaned up nicely:

Download FV-200 / Tempo VF/One operator manual (PDF) Owners and operators manual for the external VFO

The 100 W FT-200 sold in Japan for ¥69,000. The FT-200 was also sold in Australia and Europe.

The FT-200S (10 W version) was sold in Japan with a single tube in the final amplifier stage. Options included a 100 W upgrade kit for ¥3,000 and a 100 kHz crystal calibrator for ¥1,500.

The same rig was marketed in Europe by importers Sommerkamp and sold as the FT-250.

The Yaesu FT-200 is an SSB/CW transceiver covering the pre-WARC amateur bands from 80 m to 10 m. An almost all-valve design providing around 180 W PEP, good stability, and a receiver that remains a delight to use even under today’s band conditions.

The design first appeared in the late 1960s in a grey and silver case. It was also sold as the Sommerkamp FT-250 (blue case) and the Henry Radio Tempo One (black and silver). A short reincarnation in the early 1970s used an all-black case as a cheaper alternative to the first FT-101s. The FP-200 AC power pack supplied all voltages from one transformer (117 or 234 VAC) and included a front-facing loudspeaker. A 12 V power unit was also available for mobile use — 12 A on receive and up to 27 A on transmit.

Nice examples have sold for under £70 without the power pack and £100–£125 with. When properly refurbished they remain fully competent HF radios — stable thanks to the solid-state VFO, with a receiver better than many earlier solid-state offerings from Yaesu. The tuning drive is a British-made Jackson and remains smooth even after decades. The following circuit description is adapted from the Yaesu manual.

Receiving section

Signal from the aerial passes through the RX/TX relay and input tuned circuit to grid 1 of RF amplifier V2 (6BZ6). Signal is amplified and via the next tuned circuit to the grid of receiver mixer V1 (6U8 pentode). Local oscillator signal is applied to the cathode; IF signal appears at the mixer anode. The IF passes through the 9 MHz crystal filter to two-stage amplifier V104 (6BA6) and V103 (6BZ6), thence to V102A (½12AX7) as product detector with BFO on the cathode for CW and SSB. V102B (½12AX7) functions as anode-detection AGC amplifier. Detector output feeds a pulse limiter (D101, D102), AF gain control, and V101 (6BM8) to speaker or headphones.

Transmitting section

Carrier oscillator V106 (12AU7) feeds balanced modulator V107 (7360); audio from the microphone amplifier modulates the second grid. Suppressed-carrier DSB appears at the anode, passes through crystal filter XF101 to eliminate one sideband, yielding 9 MHz SSB. For AM, the balanced modulator is unbalanced and carrier frequency is shifted by varicap circuitry. For CW, audio is disabled and carrier passes through the filter. In TUNE, a 1500 Hz tone from TR503 aids alignment. After IF amplification (V104), the signal reaches transmit mixer V4 (6EJ7) with the local oscillator; output is amplified by driver V5 (12BY7) and PA V6/V7 (2×6JS6A). ALC from rectified PA grid current (D4/D5) maintains low distortion. PTT and VOX are available on phone; break-in CW keys bias and audio tone for sidetone monitoring.

Oscillator circuits

Crystal oscillators serve carrier generation and band-switched heterodyne mixing, with a self-controlled Colpitts VFO at 5–5.5 MHz for stability. External VFO model FV-200 enables split-frequency operation.

• Carrier crystal oscillator — V106 (12AU7) with 8998.5 kHz and 9001.5 kHz crystals; also acts as BFO in receive.
• Band-switched heterodyne oscillator — 2SC372 transistor on 7, 21, and 28 MHz bands.
• VFO — Colpitts with 2SC372 oscillator and buffer; varicap D401 allows ±5 kHz clarifier on receive.
• 100 kHz calibrator — 2SC367 with harmonic generator for dial checkpoints.
• AF oscillator — 1500 Hz tone for tune-up and CW sidetone; also drives VOX relays.

Mixing sequence & power

The 5–5.5 MHz VFO mixes with signal frequency on 80 m by addition and on 20 m by subtraction. On 40 m the VFO premixes with 11 MHz; on 15 m with 35.5 MHz; on 10 m with premix crystals at 42.5–44.0 MHz. An accessory socket (11-pin octal) requires a jumper between pins 1 and 2 for PA heater voltage when no accessory is connected; the same applies to the external VFO socket.

The FT-200 requires 12 VAC for valve heaters, 150 V, 300 V, 600 V for anodes, and −100 V bias — all from FP-200 AC or DC-200 12 V supplies. None require stabilization; a rebuilt supply from transformers is feasible if the original is missing or failed.

Construction

IF, TX/RX audio, and TX mixer stages share a large PCB accessible from the underside. Smaller boards carry the 9 V regulator, tone oscillator, 100 kHz calibrator, and band-switched heterodyne oscillator. RF stages, TX mixer, driver, PA, and VOX mount directly on the steel chassis. Five screws on the underside release the wraparound case for full access.

What to look for when buying

These sets are generally reliable, but watch for failure of PA grid coupling capacitor C55 (manual shows 100 pF 1 kV; 500 V parts are often found). Failure removes negative grid bias and can destroy PA valves and the mains transformer. Inspect PA valves and sniff the transformer if a power unit is included. Check around audio output V101 (6BM8) on the main PCB for leaky coupling (C103) or cathode decoupling (C101) — heat can cook the PCB until the valve hangs only by copper tracks. Examine RF trimmers through bottom case holes; ham-fisted adjustment makes realignment difficult.

Other faults: Lack of AGC often traces to grid leakage in IF valves V103/V104. Noisy band switches — spray with power off (Super Servisol, not WD-40). Total failure on one band may be an open coil in RF or pre-mixer stages. No transmit output? Check for the accessory-socket jumper — PA valve heaters must be lit.

Valve lineup

Alignment & operation notes

Semiconductors: No exotic types — small-signal NPN transistors and standard diodes; power rectifiers replaceable with BY227, 1N4007, etc.

Microphone: ¼ inch stereo jack — tip = PTT, ring = mic live, sleeve = earth.

Alignment: High voltages present — use VTVM with RF probe, signal generators, dummy load, and proper tools. Key steps include VFO alignment (TC401 coarse, TC402 temperature compensation), heterodyne oscillator trimmers, 100 kHz calibrator vs WWV, premixer V3 anode frequencies per band chart, balanced modulator null (VR106), IF and RF stages, crystal filter curves, driver and PA neutralization (TC3 with cover in place for shielding).

Operation: Three-position lever: oper / rec / cal. Receive: select band and mode, peak Grid control. Transmit: tune with mic gain minimum, dip PA current below 150 mA. On SSB/AM without mic plugged, the set may key immediately. Loading capacitor spacing is tight — prone to arcing if mismatched.

Conclusion

A highly usable radio obtainable cheaply, generally easy to repair, meeting modern standards when properly set up. Downsides: no 160 m or WARC bands; AM receive filter too narrow and transmit quality is SSB with reinserted carrier. SSB and CW performance is excellent; drift minimal after ~10 minutes warm-up. On-air SSB reports are consistently good; the receiver has low background noise and no noticeable sproggies even on 40 m.