With the info reported, the voltage drop as indicated at the back of the
radio seems a bit excessive to me. If not done so, I'd look at using at
least #12 AWG between the PS and the radio terminals. Also be sure the
connections are tight at both the PS and the radio. In my application I do
use crimp type lugs but take the extra step and solder as well as crimp. I
use #12 auto primary wire for the DC application as my DC power supply is
adjacent to the radio. Thus the power cable is only about 3 ft in length.
If your DC power cable is longer in the order of 4 ft to 6 ft or longer, I'd
opt for #10 AWG size wire. Also, be sure to have a ground connected
between the radio ground terminal and the power supply ground terminal.
This is in addition to the DC negative lead.
I'd also check the regulation at the power supply using a no load or receive
condition and then a CW key down transmit mode. Any variation there will
only get worse at the radio. With my supply I see typically a 0.05 volt
drop or less between no load and maximum load at the power supply. I use a
Astron SS-30M supply. Between the power supply and the radio typically I
measure a 0.25 volt drop on the POS side and 0.25 volt drop on the NEG side
of the DC power cable. The total voltage drop is then ~0.5 volts. By
adding the additional ground between the power supply and the radio the
effect of the IR drop on the NEG side is largely negated and thus my
effective voltage drop between the PS and the radio is only ~0.3 volts.
Somewhat historically, some of the power connectors at the radio have been
known to heat thus making for a loose connection, the result of poor a
connection. While I have not personally done so, some owners have changed
the original Tentec connector to a more favorable 30A Power Pole connector.
I recall that these are available as PC mound configuration connectors.
You will find that the radio does draw noticeably more current on some
bands, specifically the higher ones, than on others. Anticipate about a 25
amp max value while some bands will be in the order of 16 amps at 100 watts
output.
If this does not improve the issue, I'd contact Paul at Tentec Service and
inquire about a RF TX Gain alignment procedure. Before you attempt this, be
sure you have a very accurate power measuring system.
In speaking of power measurements, for my application, I have a Bird 43P
plus I use a HP RF Voltmeter to measure the RF voltage across a 50.5 ohm
Bird dummy load. With this method, doing the math, 71.0 volts is 100 watts.
73
Bob, K4TAX
----- Original Message -----
From: "art N4UC" <n4uc@hotmail.com>
To: "TenTec reflector" <tentec@contesting.com>
Sent: Saturday, October 12, 2013 8:26 AM
Subject: Re: [TenTec] Orion Power Out
Hi Rick.
RF power measurements are taken both into dummy load and well matched
antenna (SWR=1.2) . Power supply voltage at back panel connector is 13.95V
key-up, and 12.85 key-down on 10, 12.75 on all other bands. More current
being drawn at the higher power outputs. Voltage measurements taken on a
Fluke 8060A meter.
You bring up a good possibility Rick. I am reading the power output on a
TenTec 1225 wattmeter which I have not calibrated in a long while, so I
do need to do that. However, the power meter on the Orion does read 100
(full scale) on all bands except 10 and 15, where it reads about 75 % of
FS on 10 and 85 % on 15. While these may be pretty close to actual power
readings, I just take these to be values relative to FS.
Tnx es 73, Art
From: Rick@DJ0IP.de
To: tentec@contesting.com
Date: Sat, 12 Oct 2013 10:36:42 +0200
Subject: Re: [TenTec] Orion Power Out
Art, are you measuring with a dummy load attached or with an antenna?
What power supply are you using, and what are its key up and key down
voltages at the transceiver back panel?
73
Rick, DJ0IP
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of art N4UC
Sent: Saturday, October 12, 2013 5:45 AM
To: TenTec reflector
Subject: [TenTec] Orion Power Out
After getting my 565 Orion back from the factory earlier this year, I've
noticed that I only get about 50W out on 10M, and 80W on 15. All other
bands
are over 100W out. I can't say for sure what the numbers were when it
went
in and I know it's a minor nit in the grand scheme of things, but it's
the
principle of the thing especially since I don't drive an amp. Is this
typical of Orions, or is there a tweak in order?
Art/N4UC
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