Jamie,
The amp is water cooled. It is driven to provide 800 W output for the CW
signal and 200 W for the FT8 signal. The heat spreader temp rarely goes over
55 C, even in the middle of the day. Water cooling is very effective and of
course, a must for removing the heat from an enclosed case.
The much (much) bigger challenge for the amp is linearity. The CW and FT8
signals mix and create an in-band mixing (IMD) product somewhere between
1,880 and 1,896 kHz, which with poor IP3 could be a couple of Watts. (The
other mixing products are outside the band and are easily filtered.) The
signal is CW which is FM modulated by FT8.
Anyway, for anything but a very serous DXpedition, this is way too complex
and hard to set up. But when you are faced with antenna restrictions and
limited time to get on the air, it is justified.
73,
George
On Sun, 08 Sep 2024 01:28:43 +0000 WW3S wrote:
I'm still trying to wrap my head around the PTT for the amp.....and imagine the
duty cycle, that amp must be cooking !!!
73 (thanks for the N5J new one)
Jamie WW3S
------ Original Message ------
From "GEORGE WALLNER" <[email protected]>
To "Rudy Bakalov" <[email protected]>
Cc "Rudy Bakalov via Topband" <[email protected]>
Date 9/7/2024 9:14:33 PM
Subject Re: Topband: CY9C
As Jim points out: This is non-trivial.I have not published the details as so
far nobody has asked for them.
Indeed, it has to be a serious DXpedition to justify the effort needed.
George,AA7JV
On Sat, 7 Sep 2024 17:07:01 -0400 Rudy Bakalov wrote:
Is this only for 160? Are the schematics published?
Rudy N2WQ
Sent using a tiny keyboard. Please excuse brevity, typos, or inappropriate
autocorrect.
On Sep 7, 2024, at 4:59 PM, GEORGE WALLNER <[email protected]> wrote:
Rudy,Info at https://www.qrz.com/db/C6AGU73,George
On Sat, 7 Sep 2024 14:17:45 -0400 Rudy Bakalov via Topband wrote:
How does this work? IF this is indeed the case, this would be agreat solution
for multi-op contest stations.
Rudy N2WQ
Sent using a tiny keyboard. Please excuse brevity, typos, or inappropriate
autocorrect.
On Sep 7, 2024, at 2:01 PM, Jim Brown <[email protected]> wrote:
George developed a sophisticated combining network that allowed the two best weak
signal modes, CW andFT8, to operate simultaneously into the same TX antenna, and to
use the same weak signal RX antennas, allowing them tobe active all night every
night! The magnitude of this achievement technically is to realize that the two modes
areworking within 20 kHz of each other, and listening within 10 kHz, and the CW
station is running high power!
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