[AMPS] Henry Radio 10 KW RF Power Amplifier Amp#2

[Alan Gray]

In case anyone missed it, check this out if you want a good foundation for
that next amplifier project.  It seems that this unit could be had for a
very reasonable price, although shipping costs might run a bit on the high
side?

Alan, W3BV


>I saw this item for sale at eBay, the world's largest personal trading
community, and thought that you might be interested.
>
>Title of item: Henry Radio 10 KW RF Power Amplifier Amp#2
>Seller: northernwind@worldnet.att.net
>Starts: 06/14/99, 18:51:30 PDT
>Ends: 06/21/99, 18:51:30 PDT
>Price: Starts at $1,500.00
>To bid on the item, go to:
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=117719432
>
>
>Item Description:
> Second Amp#2 Manufactured by Henry Radio 10 KW 46-49 MHz RF Linear Power
Amplifer. This PA orignally cost $50,000 dollars about 12 years ago as part
of a Meteor Burst Communications System in Alaska. It was used as a STANDBY
SYSTEM as a back up to a satellite link and has very little time on the
final amplifier. The Eimac 3CX10,000B7 ceramic/metal (external anode) used
in the final stage is rated for much higher frequency operation and can be
used at 144 MHz for Amateur Radio operation (I know someone who is doing
this.) but I do not know if there is enough room inside of the Final's
chassis to convert it to 144 MHz for EME or Tropo Scatter, also the IPA is
tuned to 46-49 MHz. If you want to see a picture that I took of the type of
tube this PA uses, it is on my home page at:
http://home.att.net/~northernwind/Mvc-005l.jpg and thats no small apple next
to the tube in the photo.("This" NEW tube is also available if you want a
spare tube.) One watt of drive will power this amplifier in linear mode to
six thousand watts output. This unit was built for a continuous 6,000 watts
of linear amplifier RF output. It is capable of much more, the power supply
will allow over 3 amps at 6 KV, thats over 18,000 watts of input power to
that tube if you want it! The PA has two very large solid copper/silver
plated three or four turn coils to ground inside of its chassis, the output
power is taken off of a variable capactive coupling from a plate on the side
of the tube so changing its resonance by modifying or replacing the coils
with something else is easy. Unit uses an Eimac finals tube is rated for
10,000 watts plate dissipation and is a triode ceramic/metal flange mounted
tube. The IPA or intermediate stage uses one Eimac 5-500 tube, the
pre-driver is a solid state brick producing about 12 watts output to drive
the 5-500 when driven with one watt. This unit was used by AT&T in an Meteor
Burst master station in Alaska. It has an internal power supply which is
powered by 208 Three Phase VAC but can be converted to 240 VAC by replacing
the high voltage transformer with a 240VAC primary unit to produce 6 KV for
the final amplifier, less for the 5-500 IPA. I have been told that there is
a way to convert a three phase transformer to single phase by combining the
three primary windings in parrallel but I do not know if this is true or
not. The unit stands near 6 feet tall and contains its own internal
thru-line (Bird) and slug rated at 10 KW with meter on the front panel to
show forward and reverse RF power. This Bird Thru-line has sold for 900.00
dollars surplus all on its own at surplus sales of Nebraska without the
slug, you wouldn't even want to buy one new from Bird, it uses LC-connectors
for the output power to the filtering unit and then the thru-line and output
RF connector. Photo shows one of the front covers removed to expose the
final amplifier. Unit weighs nearly 1000 pounds crated. Located in Palmer,
Alaska. This amplfier was taken out of service working, The final amplifier
has a very expensive filtered output to reduce harmonics to exceptable
levels according to FCC rules. The RF output filter uses silver plated coils
and lots of 15KV door knob capacitors which if you had to purchase new would
cost as much as the minimum first bid price on this unit. I am one of the
technicians who took care of this unit and therefore know its history.
Possible NEW final amplifer tube available but not included in this bid. I
will hold off on selling the new tube for one week until this unit is sold.
If you want the new tube you must email me at KL7FB@att.net NOW so that I
know to hold it for you, they are over $4500.00 new but we can work out a
much lower price. I have two other used tubes which were good when pulled,
so if there is a problem, we can trade out tubes to make sure you get the
deal you are paying for but I do not see this as anything we will need to
do, it works and produces full output. Spare 3 phase 6KV transformer
available for FREE if you want one. The unit has wheels under it so can be
pushed around standing up. The crease on the right side panel shown in the
photo is of another 10KW 46 MHz PA that is also for sale on ebay, no photo
of THIS PA right now, but the unit shown on this posting is exactly like it,
minus the crease on the lower right removable side panel. Minor scratches to
cabinet here and there but over all in fair to good external physical
condition. I will email a picture of the whole thing all around and inside
of it if you ask for it. This PA must be crated for shipment via truck
>Shipping: Check for current prices from Anchorage to your location (for
1,000 pounds) via truck to get shipping costs which you would need to pay. I
have had this PA sitting in my garage for three years not wanting to sell it
hoping to eventually use it for 6 meter EME but due to circumstances am
forced to sell if I can get my price. I am a 21 year resident of the state
of Alaska and good in the last five years of call books (CD) at the same
address. I have been active in EME so if you need references, they can be
had. I just found out what the shades next to your ID mean with ebay, that
you changed your ID with them in the last 30 days! Chris Hazlitt, KL7FB
>
>
>
>
> Visit eBay, the world's largest Personal Trading Community at
http://www.ebay.com
>


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