Well it was a very simple DPDT slide switch which probably cost about 2
bucks at the time.
Here's what the manual says:
"Power HI/LO Switch - This slide switch which is located on the rear panel
of the ARGOSY selects either a nominal 50 or 5 watt output power. In the LO
position the final power amplifier is inoperative and the driver stage is
connected to the output circuits directly. Optimum operating conditions are
thus achieved for either high power or QRPp operation."
AND HERE IS HOW IT WORKS:
The driver and the final are located on the same PC board but the connection
between the two is interrupted;
...the output of the driver exits on a piece of coax and connects to the
middle pin on the right side of the switch.
...the input to the final exits on a piece of coax and connects to the top
pin on the right side of the switch.
...the output of the final exits on a piece of coax and connects to the top
pin on the left.
...the center pin on the left is the coax to the LPF board.
...the bottom two pins are jumpered.
HI-Position: Driver Out connects to Final In, and Final Out connects to LPF
line.
LO-Position: Driver Out connects to jumper, and LPF line connects to
jumper, thus connecting the driver directly to the LPF board.
So we are speaking about a $2 switch, and I doubt that they broke very
often. You don't switch it often and one should be smart enough not to
switch it under power.
BTW, I notice that the +13v line to the PA is interrupted with two pins plus
a jumper. Since the jumper is always in, in LO PWR position the PA will
draw 125mA of unnecessary power during transmit. Removal of this jumper can
save an additional 125mA. I never removed it. Would have been a good
candidate for a fuse!
Clearly Ten-Tec was QRP-minded back then and made every attempt to make one
radio be good at both.
Once the world went feature crazy and digital crazy, it made no sense
anymore to try and use a modern radio for QRP.
Battery drain on RX alone spoils your day!
It would be interesting to see what could be done today on reducing RX
battery drain when using components as used in a cell phone. Perhaps
someone has already done this. I quit following the QRP market about 15
years ago.
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Al Gulseth
Sent: Saturday, October 11, 2014 4:40 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Another retro question - Argosy-Century
The one thing that dawned on me as I read your message is whether the
inexpensive switch they used became problematic after it aged and/or
developed more contact resistance. (I would think that it would be less of
an issue at a control signal level as it was used in the later models.)
73, Al
On Sat October 11 2014 4:38:49 am Rick - DJ0IP / NJ0IP wrote:
> AL,
>
> I'm curious as to what those reasons might be. I'll ask Jack.
>
> Relying on ALC or simply backing off drive is a very inefficient way
> of consuming d.c. power.
> I thought it was rather ingenious how they implemented the "power switch"
> on the analog version.
> Actually I think Elecraft had that option in the K2 as well, but I
> can't remember for certain.
>
> Most people plan their EMCOMM from the aspect of being on the rescuing
> team. I planned mine from the aspect of being the one needing rescued.
> You see things a lot different from that side of the fence.
>
> The rescuing team assumes they will be the first responders with more
> help coming behind them.
> The victim has no idea how long it will be until he is rescued, and
> needs to plan his station for as little power consumption as possible.
>
> Here is one suggestion:
>
> The older Triton radios had a great feature; it could easily be
> converted to a true QRP rig.
>
> ...They had a short piece of RG-142 running from the output of the
> driver stage, to the input of the final 50 or 100w stage - depending
> on which Triton you had. This cable had an RCA Phono plug on it.
>
> ...The output of the final stage had a similar cable running to the
> Low Pass Filter board.
>
> ...It was a simple task to unplug the two cables and plug the driver's
> cable directly into the LPF board. You then had a QRP transceiver
> with 5 to 10w of output power. But power consumption was still higher
> than need be.
>
> ...Since the final stage was still connected to the +13v line and it
> would draw a little current as well, even though it was not in use.
> Simple
> solution: Insert an inline fuse in the thick red cable running to the
> finals.
>
> So when you needed to run QRP off of batteries for an extended period
> of time, simply remove the cabinet, plug the driver into the LPF board
> and remove the fuse to the finals. Voila! You have an efficient QRP rig.
>
> BTW, this works on the Scout as well, converting it to an Argo with 5w
out.
>
> 73 - Rick, DJ0IP
> (Nr. Frankfurt am Main)
>
> -----Original Message-----
> From: Al Gulseth [mailto:wb5jnc@centurytel.net]
> Sent: Thursday, October 09, 2014 5:07 AM
> To: tentec@contesting.com
> Cc: Rick - DJ0IP / NJ0IP
> Subject: Re: [TenTec] Another retro question - Argosy-Century
>
> That only applies to the earlier s/n (I think just analog?) units. The
> later/digital version used ALC and kept the 50W PA in line at all
> power levels. I understand that TT had their reasons for the change
> but I still prefer the PA bypass system, especially as Rick noted for
> battery operation.
>
> 73, Al
>
> On Wed October 8 2014 3:14:37 pm Rick - DJ0IP / NJ0IP wrote:
> > One feature that impressed me with the Argosy was the back panel
> > switch to switch between 50w and 5w.
> > When switched to 5w, the PA was completely turned off, which means
> > it draws current much like any other 5w radio would.
> >
> > This is much better than simply turning the power down on a higher
> > power rig.
> > This really increases batter life.
> >
> > 73 - Rick, DJ0IP
> > (Nr. Frankfurt am Main)
> >
> >
> > -----Original Message-----
> > From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Al
> > Soto
> > Sent: Monday, October 06, 2014 7:29 PM
> > To: tentec@contesting.com
> > Subject: [TenTec] Another retro question - Argosy-Century
> >
> > I liked reading all the opinions about the Corsair revisited (modern
> > version of corsair).
> >
> > I don't have a long history with ten tec and was not a ham in the
> > 80s, but now own two ten tec rigs and am thinking about another.
> > I've learned a lot just being on this reflector and am glad to be
> > part of this
>
> community.
>
> > I see the Century 21 and Argosy (analog versions) as such different
> > rigs made during the same years. For those that owned or used them
> > (for cw), how would you compare them?
> >
> > 73, Al kj3q
> >
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > 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
>
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