Clegg Climaster Zeus reviews

It has been pointed out elsewhere that this transmitter sold for the Equivalent of more than $3000 in 2015 dollars.

Every aspect of it's construction reveals why.
Wiring quality is truly first rate. The
chassis is cadmium plated steel. The dial mechanism is a split gear anti-backlash clock work. The modulator uses high level negative feedback and adjustable clipping for low distortion, high average modulation "talk power" second to none. The power supply is robust, using choke input power supply design and beefy "iron" running very conservatively.

Understand that 120 watts of AM carrier represents 480 watts PEP OUTPUT. There is no question that had this been designed as an SSB transmitter.. it would be a 500 watt PEP output device.

The VFO is mounted on a steel plate 3/16" thick. While this is still 1960's technology, using frequency multiplication, rather than hetrodyning, it represents the pinnacle of that technique, lacking only a PTO or LMO ala Collins of Heath to put it on equal footing with them.

Worth noting is that in CW mode.. the rated plate current is 250 ma.. not 200 ma used in AM Phone. This transmitter runs class C and the measured efficiency on 6m is over 65%. So you can expect 150W CW output on 6m.

Overhaul of this radio is a must if you want to put it back into service. This is easy, because there are NO paper or electrolytic caps in the RF deck... so there is nothing to do there, but to clean the switches, tube sockets and pins, lube the vfo drive mechanism, and check the tubes.
The Power supply modulator has 5 paper caps in the low level audio section, and several electrolytics used in the low and high B+ power supplies, and as cathode bypass caps in the audio section.

As high power AM/CW transmitters go.. this is not much to do. Do get a complete copy of a manual. The free copies available on line are fuzzy crap. I paid $14 for mine on ebay from R2 with free shipping.

I am NOT a modifier of classic radios, and there is little that needs it here, anymore than a Collins needs mods. However, the Ballast Tubes ( resistor in a bottle) are probably difficult to get, and/or pricey. These are used to regulate the filament voltage of the VFO. I have a suspicion that this job could be done nicely by zener diodes discretley mounted under the power supply chassis.
My opinion is resist the temptation to replace the 5R4 HV rectifiers with diodes. These tubes are very long lived, their warm up cycle provides protection for the other tubes, and they are available as military surplus at good prices.

I do admit, that I am going to investigate what it would take to provide bias so the 4x-150 could be run in class AB1 linear. AB1 is voltage driven, requiring "0" driving power.. so coupling in ssb drive from an FT-817 ought to work fine.. bringing the Zeus into the 21st century by adding high power linear operation to it's quite capable abilities on AM and CW. Finding a way to do this without drilling holes or doing irreversible damage.. that is the real challenge. I will give you more on the VFO stability after I have mine up and running. Meanwhile there is a short video showing one operating on the bench on youtube. 73 W6WUH