Richard:

You are quick with the come back today--musta had yer wheaties! grin

Through a "magic" arrangement of components--I'd like to span QRP to QRO
power... mainly... while operation remains "automatic"...

Warmest regards,
John
--
When Viagra fails to work--you are DOOMED!!!

"Richard Clark" wrote in message
...
| On Tue, 10 May 2005 09:07:17 -0700, "John Smith"
| wrote:
|
| One important use of the "coil" is a "choke", I'd hate to try to get a
| signal though a direct short of the center conductor to the shield...
|
| Hi Brett,
|
| So you have a choke.
|
| You have LEDs.
|
| You have a current limiter (that seems to fail).
|
| OK, so why the direct connection then?
|
| 73's
| Richard Clark, KB7QHC

On Tue, 10 May 2005 09:24:08 -0700, "John Smith"
wrote:

Through a "magic" arrangement of components--I'd like to span QRP to QRO
power... mainly... while operation remains "automatic"...

Hi Brett,

Automagic, more likely.

What you would like to do does not answer the why. But I will skip
that because of the more interesting ramification (kind of the
original question):
"If the FET is to limit current such that it protects the LED(s);
AND the FET fails BUT the LED(s) keep shinin' on;
What is the FET for?"

73's
Richard Clark, KB7QHC

Richard:

Without the FET, the leds would not last long, when I said "bright"--that
was an understatement...

Richard, I have to get some work done here, your exchange is fun and
interesting today--but work demands I take time to get it done (I am turning
off notification of messages--I am weak and tempted easily)--I do enjoy your
comments which are though provoking... be back later and we will continue...
grin

Warmest regards,
John
--
When Viagra fails to work--you are DOOMED!!!

"Richard Clark" wrote in message
...
| On Tue, 10 May 2005 09:24:08 -0700, "John Smith"
| wrote:
|
| Through a "magic" arrangement of components--I'd like to span QRP to QRO
| power... mainly... while operation remains "automatic"...
|
| Hi Brett,
|
| Automagic, more likely.
|
| What you would like to do does not answer the why. But I will skip
| that because of the more interesting ramification (kind of the
| original question):
| "If the FET is to limit current such that it protects the LED(s);
| AND the FET fails BUT the LED(s) keep shinin' on;
| What is the FET for?"
|
| 73's
| Richard Clark, KB7QHC

On Tue, 10 May 2005 09:43:01 -0700, "John Smith"
wrote:

Without the FET, the leds would not last long, when I said "bright"--that
was an understatement...

Hi Brett,

If by bright you mean those dim Orange LEDs you first specified, I am
inclined to believe that you have not seen "bright" at all (all
advertising claims aside). The eye is a very, very poor measurement
instrument of absolutes. All of this goes hand-in-hand with the total
lack of quantitative information of:
1. How much forward power;
2. How much reverse power;
3. How bright forward LED;
4. How bright reverse LED;
5. How much current through either LED;
6. How much voltage across anything;
7. ALL (or any) of the above for any given load.

It is one thing to "want" to build a relative indicator - but relative
to what? A Zen tune-up?

One LED gets brighter and the other dimmer? By how much? and just
what is this an indication of? I posed the acid test of describing
this in end-user documentation and I note its glaring absence.

It stands to reason that the circuit topologies that you offer the
most are biased to shut down the weaker LED (and the reverse power, by
nature of cable loss) which is guaranteed to be the weaker power.

Hence, it follows that the forward power is extinguishing the reverse
indicator. It may make an interesting display, but it is decoupled
from any purpose of revealing a mismatch.

73's
Richard Clark, KB7QHC

Richard:

Well, yeah. When I started out, I was thinking the REV LED would extinguish
at match... and while that might happen at very low power levels--I've
abandoned that idea (at least with hyperbrite leds)...

The second error I made was assuming my problem would be getting the LEDS to
glow bright enough, I mean my "other" swr meter uses a 100 ua meter--this
thinking was in slight ERROR! (just a question of how much power I want to
burn--but can always use a switch to cut out "meter" in reg operation.

And, following along that line hyperbrite LEDS were a BAD idea... those
things glow bright enough a 5 ma to read a newspaper by!!! (well, that could
be exaggerating)

Most of these designs work, some better than others--and now I accept the
fact that even a 1:1 match will just be shown as a much reduced light output
on the REV LED--I accept this and just "zen tune" for min light (still
thinking about your reccomendation for max. SMOKE!!! grin)

I am pausing here, it works, I dropped in a BUZ100 as current limiter--20+
amps max 200+v, ultra-low "R" at turn on--hard to drive at this power level
in a linear fashion--but doable, and it was in my junkbox--trying to find a
way to use this fact to my advantage--just let it try to burn that turkey
out!!! It works--but improvements are in my mind.... time for me to think
about all this and what I have learned up to this point--I have a re-newed
appreciation for swr...

I have an old tube layfayette comstat 25A boatanchor I have been going to
put on 10 meters, think I will focus on that now--will give me a 5 watt rf
source and I will drop in a switch to drop B+ so can get a ~QRP level out
the back... I will be building a vfo for it...

I need a tube set (very forgiving of high swr and direct shorts), all my
other equip is solid state and I grow careless with "the movement of the
planet Earth"

(or time grin)...

Warmest regards,
John
--
When Viagra fails to work--you are DOOMED!!!

"Richard Clark" wrote in message
...
| On Tue, 10 May 2005 09:43:01 -0700, "John Smith"
| wrote:
|
| Without the FET, the leds would not last long, when I said "bright"--that
| was an understatement...
|
| Hi Brett,
|
| If by bright you mean those dim Orange LEDs you first specified, I am
| inclined to believe that you have not seen "bright" at all (all
| advertising claims aside). The eye is a very, very poor measurement
| instrument of absolutes. All of this goes hand-in-hand with the total
| lack of quantitative information of:
| 1. How much forward power;
| 2. How much reverse power;
| 3. How bright forward LED;
| 4. How bright reverse LED;
| 5. How much current through either LED;
| 6. How much voltage across anything;
| 7. ALL (or any) of the above for any given load.
|
| It is one thing to "want" to build a relative indicator - but relative
| to what? A Zen tune-up?
|
| One LED gets brighter and the other dimmer? By how much? and just
| what is this an indication of? I posed the acid test of describing
| this in end-user documentation and I note its glaring absence.
|
| It stands to reason that the circuit topologies that you offer the
| most are biased to shut down the weaker LED (and the reverse power, by
| nature of cable loss) which is guaranteed to be the weaker power.
|
| Hence, it follows that the forward power is extinguishing the reverse
| indicator. It may make an interesting display, but it is decoupled
| from any purpose of revealing a mismatch.
|
| 73's
| Richard Clark, KB7QHC