EB104 2000w 6m amp for sale

[Lance Collister, W7GJ]

Hello!

I am in the process of getting a new portable amp for DXpeditions and a new low power
transceiver to drive it, so I am interested in selling my EB104 2kw 6m amp. It comes
with two built-in variable speed cooling fans and UHF connectors on the rear panel.
With the cooling stand I built for it (which has two fans that require 12 VDC), it
produces 1500-1600w output in Q65-60A mode. Here is the cooling stand I built for it
to provide additional cooling to enable it to operate key down for 50 second transmit
periods:

http://www.bigskyspaces.com/w7gj/EB104%20Amp%20Cooling.pdf

My goal was only to run it at 1500w on Q65-60A, but I suppose it would do more on FT8
and this video certainly suggests that it has plenty of headroom on CW or SSB (even
without the extra cooling fan base):

https://www.youtube.com/watch?v=Q04I0qnyWiI

I used a Meanwell RSP-3000-48 switching power supply with it. I have run Q65-60A (50
second key down sequences) with it at 1500w output on a DC voltage of 50 VDC, with
about 30w of drive. I also ran it with 46 VDC with slightly more drive and 57 VDC
with 23w drive. In order to make sure I did not overdrive it (the maximum allowable
drive level is 60w) with full power RF spikes, I built a 3 dB 100w attenuator to
insert between my FT857 output and the amplifier input:

http://www.bigskyspaces.com/w7gj/3dB%20100w%20attenuator.pdf

I took it with me on my 6m EME DXpedition to FO last fall, and it worked fine until
the antenna SWR went up to 1.8:1 during a heavy rain storm. That high SWR at 1500w
caused a capacitor failure on the 50 MHz Low Pass Filter board inside the amp, and I
had to bypass that board in order to stay operational. With the board bypassed, I was
only able to safely run 1200w output in Q65-60A mode for the remainder of the
DXpeditions because the LPF board also transforms impedance between the output
transistors and the antenna relays and SWR board. When I returned home, I was sent a
new replacement LPF board and have installed it.

The amp with the cooling stand weighs about 20 pounds, which is a bit heavy for an
amp that has to be transported with all the other gear in a suitcase on a DXpedition
by airplane. And to be safely transported with plenty of cushioning material, it
takes up most of a suitcase by itself. That is why I am selling it in favor of a
smaller, single transistor DXpedition amplifier.

I will sell the amp (including UPS shipping within the continental USA) for $2500.
That also includes the cooling base pictured above, the 3 dB attenuator, the DC power
cables, 2 spare cooling fans for the rear of the amp, and the PTT cable (which I also
modified to provide an additional cable to short a preamp when the amplifier is keyed
by the transceiver or sequencer). I feel obligated to tell you that this amp does not
have FCC approval for shielding, but it will easily put out the legal limit on 6 as
long as you have a good match to the antenna ;-) Serious inquiries only, please. I
prefer payment by certified check.

GL and VY 73, Lance

--
Lance Collister, W7GJ(ex WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8, E51SIX, 3D2LR, 5W0GJ, E6M, TX5K, KH8/W7GJ, V6M, T8GJ, VK9CGJ, VK9XGJ, C21GJ, CP1GJ, S79GJ, TX7MB)
P.O. Box 73
Frenchtown, MT 59834-0073
USA
TEL: (406) 626-5728
QTH: DN27ub
URL: http://www.bigskyspaces.com/w7gj
Skype: lanceW7GJ
2m DXCC #11 - 6m DXCC #815 - FFMA #7

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