Henry amp. question

Discussion in 'Amateur Radio Amplifiers' started by NM7G, Jun 25, 2012.

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  1. NM7G

    NM7G Ham Member QRZ Page

    What's the difference between an ECA 1092 plate transformer, used in some Henry amps, and transformers with P/N ECA 1092A?

    I'd really rather not go down the path about transformer reliability here; just a straightforward spec. issue if you please.
  2. N3JBH

    N3JBH Ham Member QRZ Page

    I know the 1092A is 3200 VDC @ 800 ma. But not sure what the Non A version is sorry.
  3. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    Sounds to me like they just rolled a revision ("Rev A") and there may not be any real difference, but I don't know.

    Have you checked with "Radio Dan?" He is pretty familiar with Henry BOMs...http://www.radiodan.com
  4. NM7G

    NM7G Ham Member QRZ Page

    In which model amp.? Are 3200V and 800 mA. from a manual?
  5. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    That's the rating of the entire power supply, not the transformer!
  6. NM7G

    NM7G Ham Member QRZ Page

    Of course, Steve. I was hoping to learn if that 3200/800 was with their typical tuned choke-input filter p.s.
  7. NM7G

    NM7G Ham Member QRZ Page

    If you're correct about ECA 1092 and ECA 1092A being made by different builders, it seems strange they would keep the ECA prefix(which identified a supplier, Electrical Corp. of America), when they changed to a new supplier.

    From what I've read about Henry p.s. iron, consistency wasn't a high priority. The 2K manual, for example, shows that when Peter Dahl started building 2K plate xfmrs, voltage changed from 2800 to 3kV, ostensibly not for engineering reasons.
  8. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    Do you have personal experience with that? Mine is just the opposite. I live very close to the old Henry plant in Venice, have been there several dozen times over the years, and sold them very expensive parts when much cheaper stuff was available. When I was working for Semtech, Henry selected our SDHD15KS 15kV 3A rectifier assemblies, which cost about double what Solitron, RCC and others sold them for simply because they had verified longer operating life under high temp, surge and transient conditions. They used to pay $54 each for those, with two in each amplifier. They also bought controlled avalanche assemblies from us, used a "zeners" for cathode biasing; a 50W DO-5 zener for $5 would have done this job, while our assemblies were about $15 each; but our assemblies could handle 150A peak avalanche current so in the event of a fault they wouldn't fail. They made their own roller inductor assemblies in-house which was enormously labor-intensive, and they tumble deburred all their tuning capacitors (walnut shell tumble). They actually fabricated a lot of stuff that could have been less expensively done with outsourcing.

    The chief RF amp designer from Henry is still very much in business, and running a highly successful RF amplifier company locally: ASI (Amplifier Systems Inc.) in Northridge: http://www.ampsystems.com/asiprod-old.htm He doesn't sell much into the ham market unless a ham has deep pockets and wants a very "big" amplifier (some do, and a few locals do run his stuff). His amps "start" with 3CX3000A7s and go up from there, so nothing as small as 8877s or such. The reason Henry stopped making amateur amps was mostly because Ted Henry became quite old and retired, and his stepson who took over the business wasn't a ham and evidently didn't care much about amplifiers or the family business. I think that was just typical "bad planning," as Ted Sr. just never groomed anyone to take his place. Happens all the time.

    The reason Henry made a lot of 4000W+ amps is they sold them into commercial and government markets (at higher prices, and more successfully than into amateur markets), and also they got a really good deal on piles of 3CX3000A7s. Charlie told me years ago he could buy 3CX3000A7s new from Eimac for a lower cost per tube than 8877s, so the only drawback was more filament power and a more expensive socket. But overall, even including those added costs, a 3CX3000A7 amp was less expensive for them to build than an 8877 amplifier, and the 3000A7 had 3dB more headroom when used in amateur service, which yielded some amazing IMD numbers (-43 dBc and better was typical IM3 at 1500W PEP output).
  9. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    I doubt they were making good profits once Ted Sr. left the business entirely. The younger Ted wasn't very easy to get along with, that goes back to the mid-to-late 1980s.

    As an example: Prior to the 3K Classic MK III (later called the 3K Premier), Henry never made an amp that covered 160 meters. I convinced them to by giving them an order for twelve (12) amps, giving them the choice of the 3CX1200D7 or 8877 -- either one was fine -- and the 1200D7 was a brand new tube on the market at the time (1985) so I didn't know much about it but was assured it was a good design, very rugged, and instant-on, which was a great feature. So, I gave Ted a purchase order for twelve amps (about $36,000) along with a check in that amount.

    He didn't want to take the order or the check. Finally, "Dad" agreed to the order and started the process going which resulted in their first 160-10m model. Charlie Asimoto did the design and used a HUGE 160m air wound coil in series with the roller, as well as more switched in padders at both ends. It was a success (although I don't know what they had against toroids, which would have occupied a lot less space and likely done just as well) and the amps delivered 1500W+ output easily with 55-60W drive and very smooth and easy tuning on 160. But "little Ted" rejected the order, initially.

    Charlie quit and formed his own company. With that occurrence they lost a big part of their design team.
  10. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    I suspect my last post may have put an end to crazy rants about Henry amplifiers, which I've actually found to be very reliable over 40 years.:eek:

    I think the best commercially built amp I've ever owned was the Henry 4K Ultra. Wish I still had it. It didn't cover 160m but was full coverage from 3.5 through 30 MHz and the most robust amplifier product I've ever owned, including the 30S1 and several Alphas. 1500W output was easy with 60W drive and low IMD, and it included a dual directional Bird coupler (two element version) to monitor F/R power on one of its panel meters. Even had a filament voltage adjustment and meter for that (so does the 30S1). Really nice product, we used it at multi-multi contest stations for years with many different operators and it never glitched in any way.

    I'd like to have one, again.
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