True. I think there's no RF alignment when replacing the finals in a
broad band PA, but there would be a need to set the idling bias for best
linearity.
Without the PA protection of circuit breaker, fast overloaded fuse, or
current limiting in the power supply all it takes for that "operator
error" is to cough after changing the radio band and before changing the
tuner. Or to have the family dog bark out the shack window at a squirrel
with the rig on SSB and the VOX enabled.
73, Jerry, K0CQ
On 11/21/2010 1:31 PM, d.e.warnick@comcast.net wrote:
Let's put to bed the idea that mismatched loads should not be an
issue. I have 2 Palstar tuners, an AT5K and a BT1500A. Great high
quality products. Mismatched loads "should not" be an issue. However,
switching to the wrong antenna, having a tuner set for a wrong band,
a break in an antenna wire have all happened over the past few years.
Operator error should be assumed to happen at least once in a
lifetime. That's all it takes to wipe the finals out of one of my
Omni VI+'s. I have 2 962 and 1 961 PS's. In every case to date of a
cockpit error (like having the power turned up when tuning, rather
than at 10 watts where I "thought" it was), the power supply shut
down. I had to turn PS and rig off and on to get back on the air.
Somehow that seems like a better alternative than replacing finals
and retuning or realigning. It also allows me some arrogance in
setting up a new antenna.
Just my thoughts on the issue.
Dave
WA3F
----- Original Message ----- From: "Roger Rippy"<svtincup@yahoo.com>
To: TenTec@contesting.com Sent: Sunday, November 21, 2010 8:43:02 AM
Subject: [TenTec] Power Suppy for Omni 6& tuners
At the beginning of this month, I had asked the list about tuners and
the feedback was extremely helpful. I have been operating for the
past several weeks with my new LDG Pro 200 and I am very pleased with
my decision. The tuner works well with both my Omni 6 and Triton
rigs, and it certainly has increased the ease of operation.
I understand that the older TT rigs were not built with current
protection for mismatched loads and I do have TT power supplies. My
question is in response to Jim Brown's point about using any power
supply. If you think or know that mismathed loads should not be an
issue, then what is the level of risk using a linear power supply? I
am not familiar with either an "Airpax" or an after market magnetic
circuit breaker; but I will do the reasearch since I may need to use
a non-TT power supply at some future date. I am under the impression
that TT can rebuild a 961 or 962 power supply but the cost may be
significant; therefore the linear supply option.
Roger Rippy W7RIP Bozeman, Montana
_______________________________________________ TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________ TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|