Initial Thoughts on the Used Tokyo Hy Power Amp Here for Evaluation

[Charlie Young]

I have two Tokyo HyPower amplifiers here for evaluation and testing.   I have been delayed in this project due to significant health problems, but today we made some progress.  

One of these was made in 2007 and was used by W8JA.  The other was made in late 2013 and never unboxed.  THP went bankrupt right after the purchase from HRO. 

I decided to evaluate the used amplifier first.  This amp, a HL-2.5KFX, cost about $6,000 in 2007.  It covers 160-10 with 1.5 KW output on all bands except 10M, where it is 1.2 KW.  I spent a long time reading the entire manual and studying the schematics.  I can see why this was so expensive 17 years ago now.  It also explains why they did not sell large numbers of these compared to lower price units like Ameritron.   Then later Elecraft came in with a 1.5KW unit with somewhat lower cost, although still expensive.  It does not appear to me that THP spared any expense in designing and building these  1.5 KW out amps. 

W8JA used this amp for many years and had no trouble with it to my knowledge.  It just sat on the desk and played.  In reviewing the design, it is very robust and well protected.  I have not tested it yet but will be shocked if it is not fully operational now.  In fact, the amp could not be distinguished from new.  All the boxes, documentation, rig cables are present and in pristine condx. 

What about the age of the amp?  I checked Mouser and Digikey, and both show the two output devices (Microsemi ARF-1500) as in stock at about $300 each.  In the schematic, the individual components are listed with their OEM part numbers, so I am certain these parts are available from standard sources.  The design of this is modern, not a bunch of lower power discreet transistors in parallel like was common in the past.  I am personally confident I could keep this amp running and get parts for it.  There are likely a number of ham radio repair vendors who could do the same.  

Before or after I test this, we will remove the cover and take pictures.  For example, I want to get a picture of the solid copper heat sinks the Microsemi devices are mounted on.  

As for protection, this has a microprocessor monitoring many parameters to protect the finals.  Device current, temperature, voltage, drive level, load VSWR, proper band selection, etc.  If anything is amiss, it shuts down immediately.  

I am impressed with this and would love to own it 🙂.    How could I justify another amplifier to myself?    

We will post test results and interior/exterior pictures. 

This is probably the best designed and constructed amplifier that I have seen.   Obviously, I have not seen them all. 

73 Charlie N8RR