Carl,
I understand that the SWR as shown on the meter in the transceiver is
high when the amplifier is operating, but the SWR on the line to the
antenna is normal. Is that correct?
The Henry Ultra amps have pi-network input circuits for each band. They
have adjustable coils, L1-L6 on the schematic. If someone has
misadjusted them, you can see high SWR.
Does this happen on all bands or just some of them?
73,Victor, 4X6GP
Rehovot, Israel
Formerly K2VCO
CWops no. 5
http://www.qsl.net/k2vco/
On 11/12/2023 18:08, Carl Braun wrote:
Hello John
I am seeing high VSWR on my 7800 when using the Henry ULTRA amp. I don't hear
or see RFI on my monitored signal but the VSWR meter is certainly responding
differently to the Henry amp than it does to my Alpha amp. By engaging the
tuner on the 7800 I can get MOST of the Henry's VSWR down to under 1.5 or so.
Placing a W2FMI line isolator (1:1) in between the 7800 and the Henry did
nothing to lessen the high VSWR I saw coming back at the transceiver. It
should be noted that the RF console was approx. 3' from the transceiver at the
time of testing with a 25' RG-58 exciter coa from the rig to the input of the
amp.
I've pulled my dummy load out of storage and am ready to test the amp with
that. The antennas I have been using with the Henry are all flat at their
respective frequencies. I see less than 1.3:1 at 1.5KW on my Powermaster II
monitor, and on the 7800 VSWR meter, when using the Alpha. Palomar is sending
over a couple of choke kits for the radio room and the antenna feeds. Choke
kits for the TXCVR and AMP as well as 1:1 chokes for vertical antenna feed
points. As one responder noted; Henry basically suggests you don't use the
tuner in the TXCVR to knock down any VSWR. I plan on asking Dennis Pickering
about the issue next time I have him on the phone.
More experimenting later this week as I am currently wiring in a 240VAC feed on
the opposite side of the radio room so I don't have to test the Henry consoles
in close proximity of the operating position. More updates afterward.
Carl W9LF
-----Original Message-----
From: Amps <amps-bounces@contesting.com> On Behalf Of john@kk9a.com
Sent: Wednesday, December 6, 2023 9:43 PM
To: amps@contesting.com
Subject: Re: [Amps] Starting up a NEW Henry amp
[You don't often get email from john@kk9a.com. Learn why this is important at
https://aka.ms/LearnAboutSenderIdentification ]
CAUTION: This email originated outside of the organization. This message might
not be safe, use caution in opening it. If in doubt, do not open the attachment
nor links in the message.
Are you saying that the Henry is causing RFI in your transceiver? Is this
occurring with a dummy load or does you antenna feedline have CMC?
John KK9A
Carl Braun W9LF wrote?
By enabling the tuner in the rig I can knock down most of the SWR when running
the Henry's but I don't have to do that with my other amp. One difference... I
do have a longer coax run (25') from the Henry's back to the PM II watt meter .
The Alpha has a three ft (3') jumper from the amp to the watt meter. I'm going
to shorten the coax from the Henry RF consoles to the coupler to 8' or so to
see if that lessens any of the RF coming back to the rig. I do have a W2FMI
line isolator in the line going to the amps with no visible changes. More parts
are coming like RFI kits for the amp and transceiver, a 1:1 unun for the output
of the amp and one for the base of the antenna.
Any other Suggestions?
Thanks
Carl W9LF
_______________________________________________
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
|