Fuqua, Bill L wrote:
> Heathkit's death was due to the fact that advances in manufacturing
> techniques took away the financial incentive to build a kit.
> The first hint of this was in some of the earlier Heathkit catalogs. One
> kit, an All American Five, radio receiver actually cost more in kit form
> than assembled. It was around $10.
> Another thing that kept Heath Kit going for a while was the educational
> programs using their kits.
Those were very good courses too. I used the theory courses to teach
the skilled trades every thing from introductory electricity through
digital circuit design with Boolean Algebra. I still have the books,
except for one which I loaned out and never got back.
73
Roger (K8RI)
> Vietnam Vets coming home were able to
> take mail order classes in radio and TV for free via VA educational program.
> One of these was a well known way to get a free color TV set which
> those days was very expensive. Some took the classes just to get the Color TV
> Kit.
>
> 73
> Bill wa4lav
> ________________________________________
> From: amps-bounces@contesting.com [amps-bounces@contesting.com] On Behalf Of
> Alek Petkovic [vk6apk@bigpond.com]
> Sent: Sunday, January 31, 2010 7:48 PM
> To: Charles Harpole
> Cc: amps@contesting.com
> Subject: Re: [Amps] why did Heath die?
>
> That's easy to answer.
>
> People don't wanna build stuff.
>
> I have a table at our hamfest every year and I sell used and new bits
> and pieces that hams can use in their construction projects . Mainly
> amplifier and high voltage stuff.
>
> Out every 100 people that go past, only 5 will look at the stuff and
> 2 will buy something. My prices are dirt cheap as my motive is not to
> make money but rather give the builders in our small ham community
> access to stuff that is hard to find and that they would have to pay
> an arm and leg for elsewhere.
>
> We all have too much money these days. There is no incentive for most
> people to build when they can buy so easily.
>
> 73, Alek
> VK6APK
>
>
> At 08:37 AM 1/02/2010, Charles Harpole wrote:
>
>
>> Why did Heath kit die?
>>
>> Charles Harpole k4vud@hotmail.com
>>
>>
>>
>>
>>> Date: Sun, 31 Jan 2010 19:25:59 -0500
>>> From: sub1@rogerhalstead.com
>>> To: garyk9gs@wi.rr.com
>>> CC: amps@contesting.com
>>> Subject: Re: [Amps] Good amp to buy
>>>
>>>
>>>
>>> Gary K9GS wrote:
>>>
>>>> This has been an interesting thread. Along the same lines.....I
>>>>
>> wonder why
>>
>>>> someone doesn't offer a well engineered kit amplifier?
>>>>
>>> The same reason Heath doesn't sell kits any more. Economics! Those who
>>> build are a very small number.
>>>
>>>> Basically a
>>>> modernized SB-220 possibly using different tubes?
>>>>
>>> Actually the 3-500 is still the most popular tube, it's relatively
>>> inexpensive and fairly tame and with enough voltage it'll run the legal
>>> limit without straining.
>>>
>>>> Is there possibly some
>>>> FCC regulation preventing this??
>>>>
>>>>
>>>>
>>> Nope! It would require the FCC's blessings just like the ones being
>>> sold, but that's the only requirement.
>>> However, how many hams do you know that you would be comfortable with,
>>> poking around inside your amp with all that high voltage? I have an
>>> idea that at least part of the problem is our litigious (sp?) society.
>>> Maybe not the ham, but relatives and next of kin. Even signed Waivers of
>>> Liability offer very little protection from the one signing it and none
>>> from the next of kin.
>>>
>>>> Maybe two models, a KW class and a legal-limit class.
>>>>
>>> Heath did that for years and closed shop. Maybe there's now a niche
>>> market for something like these, but it'd likely be a small portion of
>>> the overall market for amps. Would the market be large enough to support
>>> those doing it? Most current amps are built by relatively small
>>> operations, so it'd have to be small as well. Maybe two or three hams
>>> could do it, but remember it would have to survive the cost of receiving
>>> the FCC's blessing and make enough money to keep the families of those
>>> involved happy. It takes business and market savvy as well as a
>>> thorough understanding of amps to do something like this. Then there is
>>> the problem of "how rugged an amp or amps would you sell in kit form?"
>>> There will always be those who will push an amp for everything it can do
>>> which may be well beyond the ratings of the tube(s) and/or power supply
>>> and then blame the manufacturer for providing parts of insufficient
>>> capability. It reminds me of the early 8877's that had higher gain and
>>> lower drive requirements. Some hams were driving them with the full
>>> output of their exciters as the tube would do it even though it could
>>> reach its design limits with something like 50 watts or less and those
>>> things will put out about 2200 watts. I believe it was Carl who said
>>> Some one was blaming it on parasitics.
>>>
>>>> Perhaps even a solid
>>>> state AMP.
>>>>
>>>>
>>>>
>>> Solid state is a different animal. The transistors are expensive and
>>> very fragile. Given a big voltage spike and a tube will normally just
>>> ignore it. They might blush a bit if you drive them too hard, but
>>> recover quickly (most times) Even the expensive, high powered
>>> transistors can be wiped out from the static you pick up walking across
>>> the floor. Even a microsecond of too high a voltage will take them out
>>> and maybe no more than a few milliseconds of excess current. Even the
>>> large, high power transistors are small physically and that makes heat
>>> transfer to the heat sink problematic even when using exotic heat
>>> transfer compounds such as "Arctic Silver" which is expensive.
>>> I use it on CPUs and it's very effective. Given a legal limit amp you
>>> have to get rid of the heat through an area that is likely to be less
>>> than 2% to 5% of the radiator area on a single, small, power tube like
>>> the 8874.. So you parallel two transistors to run the power that one is
>>> capable of just to get enough area to safely transfer the heat. Even
>>> then the delta T is pretty high. Then run them push pull. The Tokyo
>>> Hy-Power HL-1.5Kfx gets 1KW PEP and CW output on HF from just 4
>>> transistors. I can purchase a much more rugged 4CX-1500 for less money.
>>> You will probably spend nearly as much on the protective circuits as the
>>> whole rest of the amp. The basic amplifier runs about the power level of
>>> entry level amps and costs about $3,000. To add the capability of
>>> running the legal limit with some excess capacity now called overhead,
>>> more than doubles the price.
>>> The no tune, instant on, auto band switching, legal limit amps are
>>> great, but they come at a price and not just the monetary one. They
>>> require a low SWR to get maximum power out and by low I mean less than
>>> (>)1.2:1, more often, less than 1.1:1. That means an antenna tuner and
>>> retuning even after minor excursions 20 KHz or so on 40 meters. Of
>>> course there is now the auto-tuner which is also fantastic and almost a
>>> necessity for solid state amps if you do much moving around on 160, 75,
>>> and 40 meters. OTOH I did it with a pair of MFJ 989C tuners and an
>>> antenna analyzer and it worked very well. Switch in the noise bridge,
>>> adjust tuner, switch back to amp with no additional tuning. No on the
>>> air signal required at all.
>>>
>>> There are some adventuresome hams (couple even here on the reflector)
>>> who are working on some solid state amps at the legal limit level. Even
>>> with help from some well known manufacturers it's a rather daunting task.
>>>
>>>> The kit amplifier would be able to purchase components in
>>>>
>> volume, keeping
>>
>>>> the cost down.
>>>>
>>>> Anyone know how many amps Heathkit sold anyway?? I'll bet it was a lot.
>>>>
>>>>
>>> We now live in a different society as hams and individuals. Would what
>>> worked then, work now. Remember Heath started out small and grew like
>>> crazy in size and offerings. Then the market dried up abruptly. This was
>>> about the same time the attendance for most swaps dropped off and became
>>> more tire kickers than really interested purchasers. This did not
>>> coincide with the economy dropping off either. It did coincide with
>>> what a couple of manufacturers did though. Whether by chance, I don't know.
>>>
>>> 73
>>>
>>> Roger (K8RI)
>>>
>>>
>>>> 73,
>>>>
>>>> Gary K9GS
>>>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>>> K9GS
>>>> Gary Schwartz email: k9gs (at) arrl.net
>>>> Check out K9NS on the web: http://www.k9ns.com
>>>> Society of Midwest Contesters (SMC) http://www.w9smc.com/
>>>> GMDXA http://www.GMDXA.org
>>>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>>>
>>>> ----- Original Message -----
>>>> From: "Edward Swynar" <gswynar@durham.net>
>>>> To: <Gary@ka1j.com>; <amps@contesting.com>
>>>> Sent: Wednesday, January 27, 2010 1:03 PM
>>>> Subject: Re: [Amps] Good amp to buy
>>>>
>>>>
>>>>
>>>>
>>>>> "...What do you recommend as a good HIGH power amp?"
>>>>>
>>>>> **********************************
>>>>>
>>>>> "Roll y'er own!" I say...
>>>>>
>>>>> The venerable, tried & true 813 is still available both new, surplus, at
>>>>> Hamfests, etc. Two of these in parallel grounded-grid will give you
>>>>> 600-watts output, four will up the ante to 1.2-kilowatts.
>>>>>
>>>>> They're practically "free", too, compared to the prices of
>>>>>
>> modern 3-500Zs,
>>
>>>>> 8877s, etc.
>>>>>
>>>>> And don't let their high internal output capacitance scare
>>>>>
>> you: there are
>>
>>>>> ways to make them play just as efficiently on 10-meters, as they do on
>>>>> 160.
>>>>>
>>>>> ~73~ de Eddy VE3CUI - VE3XZ
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Amps mailing list
>>>>> Amps@contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>
>>>>>
>>>> _______________________________________________
>>>> Amps mailing list
>>>> Amps@contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>
>>>>
>>>>
>>> _______________________________________________
>>> Amps mailing list
>>> Amps@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>>>
>> _______________________________________________
>> Amps mailing list
>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>>
>
>
> http://www.qrz.com/db/vk6apk
> http://www.qrz.com/db/vk6py
>
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|