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Author Topic: Heathkit rebooted  (Read 12208 times)

Jeff Bankston

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Re: Heathkit rebooted
« Reply #30 on: January 01, 2014, 03:23:36 pm »

EAW builds passive filter networks that way... on scrap wood... or at least they have done so in the past.
AR use to build the speaker crossovers on a piece of thin press board. i had a pair of AR-5 speakers and still have my AR-58 cabinets and mid drivers and x-over parts. the coils are hand wound and its a sloppy job.
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Lyle Williams

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Re: Heathkit rebooted
« Reply #31 on: January 01, 2014, 03:45:07 pm »

There are lots of different styles of low-volume or noncommercial construction that don't involve printed circuit boards.

Two that I use for one-off circuits are:

Dead bug:  glue all the multipin components to a square of scrap board with their legs pointing in the air (hence the name dead bug).  Solder resistors and point-to-point wires as required to complete the circuit.

Manhattan style:  take a sheet of copper clad board material and use it as the groundplane.  Glue on tiny squares of circuit board anywhere you need non-grounded connections.
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Mike Sokol

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Re: Heathkit rebooted
« Reply #32 on: January 01, 2014, 04:47:45 pm »

There are lots of different styles of low-volume or noncommercial construction that don't involve printed circuit boards.

Don't forget Altoids boxes:

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Mike Sokol
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Stephen Swaffer

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Re: Heathkit rebooted
« Reply #33 on: January 03, 2014, 10:03:34 am »

For those impatient types out there there are  few unbuilt Heathkits on Ebay-seeing the prices its no wonder Heathkit is planning to start making them!
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Steve Swaffer

Steve M Smith

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Re: Heathkit rebooted
« Reply #34 on: January 03, 2014, 10:15:50 am »

i had a pair of AR-5 speakers

I have a set of AR-3a speakers which the previous owner left in a house my mother bought a few years ago.  They sound great.


Steve.
« Last Edit: January 03, 2014, 10:18:28 am by Steve M Smith »
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John Roberts {JR}

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Re: Heathkit rebooted
« Reply #35 on: January 03, 2014, 10:26:52 am »

I've got one AR-4 sitting in my kitchen. Several decades ago I set up my parents with a nice hifi system using a pair of these with a decent Jap receiver, turntable, etc. Their house got robbed and the dumbass crook only took one of the speakers. So I ended up with the orphan AR-4 and don't have the heart to throw it away.

JR 
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Don't tune your drums half-ass. Listen to what a properly "cleared" drum sounds like.   http://circularscience.com/

frank kayser

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Re: Heathkit rebooted
« Reply #36 on: January 03, 2014, 02:15:05 pm »

Ah yes, Dynaco.  They used to be a very hot ticket in stereo pre-amps.  My dad taught me to solder when I was in Jr high school (grade 7 or 8 ).  In 11th grade, my friend and I were all about stereo - speakers, amps, blah blah.  He decided he would buy a Dynaco pre-amp for me to build.  Toughest thing I had built.  Looking back, it was a great kit with great instructions.  As I remember, specs were very close to McIntosh.  Probably got that wrong, but...

Heathkit fuzz pedal?  Great die-cast case with wrinkle finish.  Problem was it did not provide a volume boost with fuzz (then only used for lead riffs), but rather the volume was cut significantly.

How about H89 computer?  All in one, 48k ram, 2ghz 8080 processor, 90k single sided hard-sectored disks, green on black 80x24 screen communicating with the CPU at a blinding 9600 baud! All that for a measly $2,500! Add $200 for the extra 16k ram.  Couldn't afford the $300 for the soft-sectored controller. The terminal board and the CPU board came assembled.  You built the power supply, all the high voltage supply for the CRT - basically everything in the hard-foamed molded case.  I chose C/PM over HDOS.  Wee ha.

Immediately I had a problem with the thing just resetting itself randomly.  Heathkit got it at least three times, checking the power supply (good we had a store nearby). They'd put a test pattern on it and leave it sit, waiting for a fault. Weeks at a time.  None there.  Get it home, and within 5 minutes, bang.

Must be the house power.  Bought an expensive power strip.  Nope.  Fought with the power company - finally they came out and put a "dot recorder" on my power panel - measured voltage every five seconds or so, and had a pen and graph paper where the pen would drop and make a dot on the paper.  To them, voltage was fine.  Nearly a straight line.  Of course they then said their grid was not designed for clean power for computers.  Try an isolation transformer.  More big money (for me) - well over $100 anyway.  Zip.  Still a problem.  Back to Heathkit.  No ideas.  I started thinking... C/PM loaded at a different address than HDOS - which was what they were testing with.  Memory?  Heck with it. This called for the shotgun approach.  I got some contact cleaner, pulled each chip on the motherboard one-by-one, CPU, memory, every single chip, dipped the legs into the cleaner, and reseated the chips.  No more problems!!

I let the techs at Heathkit know how I solved the problem, and suggested they change their testing protocol.  Tech was moving on!  Hot-rodded it with 19.2k baud comm between CPU board, and got a kit for a plug-in 4mhz Z80 processor, and two half-height floppys.  Still have it.  Couldn't part with it.  I shudder to think how much I've spent on computers over the years...

frank

 
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Steve M Smith

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Re: Heathkit rebooted
« Reply #37 on: January 03, 2014, 02:18:56 pm »

I've got one AR-4 sitting in my kitchen.

My memory is not what it used to be.  I just had a look at my speakers and they're AR-4Ax, not AR-3x!


Steve.
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John Roberts {JR}

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Re: Heathkit rebooted
« Reply #38 on: January 03, 2014, 02:34:57 pm »

I see your H89 and raise you to my old H-11. The H-11 was heatkit's version of a DEC LSI-11/2 crude early 16b (mini?) computer. It even had a paper tape reader option. I bought the dual 8" floppy drive and that cost more by itself than your whole computer. I bought a memory PCB from a 3 rd party company and paid about $1k for a full load 32k of ram. IIRC the computer could only use about 28K of that ram. The other 4k addresses were used for other CPU management.

I doubt anybody reading this has a cell phone limited to only 32k of memory. :-)

The complete system cost me between $6k and $7k. Most of it was kit... the memory card and dual floppy was the only part pre-assembled. I recall having to repair the monitor once when the darlington power transistor in the flyback circuit released smoke... Since heathkit was backordered weeks on a repair part , I ended up rolling my own darlington from two normal transistors. Fun and games...but I wasn't going to go without my computer for weeks. 

I finally carted this out the the curb about a year ago. There were collectors interested in the old iron, but none interested in paying what it would cost to ship, and some of the components were fragile so not easy to pack and ship safely.

 JR
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Don't tune your drums half-ass. Listen to what a properly "cleared" drum sounds like.   http://circularscience.com/

John Roberts {JR}

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Re: Heathkit rebooted
« Reply #39 on: January 03, 2014, 02:35:50 pm »

My memory is not what it used to be.  I just had a look at my speakers and they're AR-4Ax, not AR-3x!


Steve.

Now we know where 3 of them are... :-)

JR
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Don't tune your drums half-ass. Listen to what a properly "cleared" drum sounds like.   http://circularscience.com/

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Re: Heathkit rebooted
« Reply #39 on: January 03, 2014, 02:35:50 pm »


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