Lafayette KT-200 / Trio 9R-4J
Written by Bryce Ringwood   

These once popular radios were sold in kit form as well as pe-assembled. They were designed for Lafayette by Trio/Kenwood. They look like a Hallicrafters S-38  but that is really a different radio altogether. I believe the KT-200 was the kit version of the HE-10. If so, someone made a nice job of assembling this one. They were available from about 1959 to 1964.

Coverage is 4 Bands: 550kHz-1.6MHz, 1.6MHz - 4.8MHz, 4.8-14.5MHz and, 11-30MHz.  The IF is 455kHz.

Valves

RF Stage - 6BD6

IF(2) - 6BD6

Oscillator - 6BE6

Mixer - 6BE6

Detector - 6AV6

BFO - 6AV6

Output - 6AR5

Rectifier - 5Y3 

Giving a total of 9 valves. The 6BA6 can be substituted for the 6BD6, and the 6AT6 can be used instead of the 6AV6 in an emergency. I don't recommend you substitute anything for the 5Y3. Remember that substituting valves can alter the performance in surprising and confusing ways!

Controls

Main and bandspread tuning

Band change

Volume/ On-OffLafayette KT-200 from the top

IF Gain

AVC/MVC/BFO

Noise Limiter

BFO Tune

Stand-by

S-Meter Zero

The set has an S-Meter calibated in db

 

Faults

This particular radio had a number of problems, fortunately all minor. The bandspread tuning capacitor was shorted to ground - the vanes had been slightly bent and were easily straightened. It would not receive anything on the highest bands. This was cured by cleaning the wavechange switch contacts Finally,  the AVC would not work. This was quickly traced to a leaky decoupling capacitor and replacing it brought the set back to life.  Someone had used mains cable instead of wiring wire to rewire part of the set, so this was neatened up.

Review

This is intended to be an AM or CW receiver, presumably for beginners. Using it for SSB is tricky, because you have to back off the IF gain until the signal is at the right level - all at the same time you are trying to tune in to the signal. So, whilst it might not be a great radio for hams, it is a nice set for general broadcast listening. The bandspread tuning makes it very easy to use. Like many valve sets, the sensitivity falls off above 15 metres. (The specification for sensitivity is 13 microvolts - not spectacular.)  It is small and light, which makes it convenient for today's smaller homes.

You might want to look at the Hallicrafters S38, which looks the same (well, similar) but is different internally.  This was made in 1946.

 
Joomla template by a4joomla