In article ,
dxAce wrote:

"Charles W. Hinkle" wrote:

I have used Mini Circut Labs ZFSC-2-1 and a 2 port passive Stridsberg. I
obtained the MCL's at hamfests for $10 and the Stridsberg new Presently I
am using a MCL PSC-3-1 to feed 3 receivers. I also got this at a hamfest.
My receivers make up the nearly 5 db loss.

How do they make up the loss? Just curious.

Maybe his radios have pre-amps like the Drakes.

When you use a passive splitter the loss is 3dB power and 6dB voltage. I
think most radio S meters are responding to the voltage number due to
the nature of the AGC circuits. Someone can correct me on this. Should
be easy enough to take a splitter in and out of line.

--
Telamon
Ventura, California

Telamon wrote:
Maybe his radios have pre-amps like the Drakes.

When you use a passive splitter the loss is 3dB power and 6dB voltage.
I
think most radio S meters are responding to the voltage number due to
the nature of the AGC circuits. Someone can correct me on this. Should
be easy enough to take a splitter in and out of line.

--
Telamon
Ventura, California
------------------------------------------------------------
Almost all modern receivers use teh AGC voltage for the
"S-meter". And very few have any meaningfull calibration.

Terry

wrote:

Telamon wrote:
Maybe his radios have pre-amps like the Drakes.

When you use a passive splitter the loss is 3dB power and 6dB voltage.
I
think most radio S meters are responding to the voltage number due to
the nature of the AGC circuits. Someone can correct me on this. Should
be easy enough to take a splitter in and out of line.

--
Telamon
Ventura, California
------------------------------------------------------------
Almost all modern receivers use teh AGC voltage for the
"S-meter". And very few have any meaningfull calibration.

Yes, the calibration may indeed be off with various manufacturers, however all
things being equal it should be very easy to determine various antenna changes
with a 'particular' receiver.

Damn simple.

dxAce
Michigan
USA

dxAce wrote:
dxAce Apr 17, 3:11 pm show options
Newsgroups: rec.radio.shortwave
From: dxAce - Find messages by this author
Date: Sun, 17 Apr 2005 18:11:26 -0400
Local: Sun,Apr 17 2005 3:11 pm
Subject: splitter ?
Reply | Reply to Author | Forward | Print | Individual Message | Show
original | Report Abuse

- Hide quoted text -
- Show quoted text -
Yes, the calibration may indeed be off with various manufacturers,
however all things being equal it should be very easy to determine
various antenna changes with a 'particular' receiver.

Damn simple.

dxAce
Michigan
USA
---------------------------
Sadly very few radios have S-meters that behave in a "correct" way.
I have a HP calibrated step attenuator, with .5dB steps. Zin 50Ohm
Zout 50 Ohm. When checked at the electronics lab (at UK) the
error was less then .07dB worst case. I have a simple crystal osc that
is very temp stable. Zout 50 Ohms at .1V. Measured to be 0.10V.

I have had chance to check quite a few receivers. From the famous
R390, to one of the Lowe 150s. I would have to dig out my notes, if
I even still have them, and the R390 was the ony one that tracked
6dB/1S unit.

This url has better data then I can dig out out the moment:
http://www.ac6v.com/sunit.htm

Unless you know, that is have measured, your S-meter, it is only
a rough indication.

You can clearly use your S meter to compare one antenna to another,
but I would be very hesitant to say that "antenna 1 is S2 and antenna
2 is S6, therefore antenna 2 has 24dB more gain then antenna 1."
Based on the assumption that 1 S unit equals 6 dB.
S6-S2=4 S-units, 4 X6dB = 24dB
(Math shown for those new to the hobby)

Now if you have a calibrated step attenuator you could show that:
Ant 1 gives S2
Ant 2 requires 20dB of attenuation to give a reading of S2.
Ant 2 has about 20dB more gain then Ant 1.

I bought my Hp attenuator at a surplus store for $5.
I bought 2 fox industries 50P-077 +12V BCD attenuators
that have a measured error of less then .01dB for $1each!
Coupled with some Pasternak PE7101 coaxial relays I hope
to be able to some "meaningfull" antenna experiments this
summer and next winter.

There is a vacant lot caty corner behind us and I have permission
from the lot owner, and both my rear and next door neigbors to run
an temp antenna to and across that lot. I will be able to get about
300' of wire up in a straight line. I intend to see just how length
effect
signal strength.

Next fall a frined is going to let me spend a few weekends on his
fields to check even longer wires.

Terry

wrote:

dxAce wrote:
dxAce Apr 17, 3:11 pm show options
Newsgroups: rec.radio.shortwave
From: dxAce - Find messages by this author
Date: Sun, 17 Apr 2005 18:11:26 -0400
Local: Sun,Apr 17 2005 3:11 pm
Subject: splitter ?
Reply | Reply to Author | Forward | Print | Individual Message | Show
original | Report Abuse

- Hide quoted text -
- Show quoted text -
Yes, the calibration may indeed be off with various manufacturers,
however all things being equal it should be very easy to determine
various antenna changes with a 'particular' receiver.

Damn simple.

dxAce
Michigan
USA
---------------------------
Sadly very few radios have S-meters that behave in a "correct" way.
I have a HP calibrated step attenuator, with .5dB steps. Zin 50Ohm
Zout 50 Ohm. When checked at the electronics lab (at UK) the
error was less then .07dB worst case. I have a simple crystal osc that
is very temp stable. Zout 50 Ohms at .1V. Measured to be 0.10V.

I have had chance to check quite a few receivers. From the famous
R390, to one of the Lowe 150s. I would have to dig out my notes, if
I even still have them, and the R390 was the ony one that tracked
6dB/1S unit.

This url has better data then I can dig out out the moment:
http://www.ac6v.com/sunit.htm

Unless you know, that is have measured, your S-meter, it is only
a rough indication.

Yes, of course. (No ****, Sherlock)

You can clearly use your S meter to compare one antenna to another,
but I would be very hesitant to say that "antenna 1 is S2 and antenna
2 is S6, therefore antenna 2 has 24dB more gain then antenna 1."

No one was trying to say that.

Based on the assumption that 1 S unit equals 6 dB.
S6-S2=4 S-units, 4 X6dB = 24dB
(Math shown for those new to the hobby)

Now if you have a calibrated step attenuator you could show that:
Ant 1 gives S2
Ant 2 requires 20dB of attenuation to give a reading of S2.
Ant 2 has about 20dB more gain then Ant 1.

I bought my Hp attenuator at a surplus store for $5.
I bought 2 fox industries 50P-077 +12V BCD attenuators
that have a measured error of less then .01dB for $1each!
Coupled with some Pasternak PE7101 coaxial relays I hope
to be able to some "meaningfull" antenna experiments this
summer and next winter.

There is a vacant lot caty corner behind us and I have permission
from the lot owner, and both my rear and next door neigbors to run
an temp antenna to and across that lot. I will be able to get about
300' of wire up in a straight line. I intend to see just how length
effect
signal strength.

Next fall a frined is going to let me spend a few weekends on his
fields to check even longer wires.

Yes.. but you wasted most of the space above to say nothing.

Boggling to say the least...

I'm more and more amazed here everyday.

Continue to tote.

dxAce
Michigan
USA

- Hide quoted text -
- Show quoted text -
************************

thanks to one and all for some great info.
i need to study on this. i found an old article
in the july/04, NASWA Journal. get my facts together
here, and move to there. would be fun to build when
i find the time. thanks again...
Drifter...

On Mon, 18 Apr 2005 00:12:32 GMT, Drifter wrote:

- Hide quoted text -
- Show quoted text -
************************

thanks to one and all for some great info.
i need to study on this. i found an old article
in the july/04, NASWA Journal. get my facts together
here, and move to there. would be fun to build when
i find the time. thanks again...
Drifter...


Now that the dust has settled a little bit and the belligerents are
hopefully being triaged.....

Please read the spec sheets on the prospective splitter you intend on
using or, if rolling your own, look at the design. Many splitters
claim to have "only" a 3 or 5 dB loss, but that's only "best case."
Often times, the loss will vary greatly across the operating range of
the splitter (and sometimes the impedance!). For HF and MF, the
losses are usually not too bad.

If you plan to use a preamplifier, PLEASE (!) use a low noise model.
Often times preamps will raise the noise floor by several dB, which
could wipe out some weak DX for you. Purchase (or build) the BEST
preampllifier that you can. It should be low noise, and the gain
should not be so high that it goes into oscillation (you really just
want to overcome the splitter losses). Some preamps will cause
trouble with the 3d order intercept points of your receiver by
overloading the front end. Every active component plays against
every other active component, so be mindful of your trade-offs and
gains.

Good luck!

Al in CNMI

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Telamon wrote:

In article ,
dxAce wrote:

"Charles W. Hinkle" wrote:

I have used Mini Circut Labs ZFSC-2-1 and a 2 port passive Stridsberg. I
obtained the MCL's at hamfests for $10 and the Stridsberg new Presently I
am using a MCL PSC-3-1 to feed 3 receivers. I also got this at a hamfest.
My receivers make up the nearly 5 db loss.

How do they make up the loss? Just curious.

Maybe his radios have pre-amps like the Drakes.

When you use a passive splitter the loss is 3dB power and 6dB voltage. I
think most radio S meters are responding to the voltage number due to
the nature of the AGC circuits. Someone can correct me on this. Should
be easy enough to take a splitter in and out of line.

Correct me if I'm wrong... but would it not be better to run some
pre-amplification ahead of the splitter rather than try to make up something that
has already disappeared? Much the same in say VHF work where it is better to run a
receive pre-amp right at the antenna versus running it at the receiver end of the
coax?

I'd never consider using a passive splitter here, and I rarely if ever engage the
pre-amps on the receivers... no need.

dxAce
Michigan
USA

On Sun, 17 Apr 2005 18:06:44 -0400, dxAce
wrote:



Telamon wrote:

In article ,
dxAce wrote:

"Charles W. Hinkle" wrote:

I have used Mini Circut Labs ZFSC-2-1 and a 2 port passive Stridsberg. I
obtained the MCL's at hamfests for $10 and the Stridsberg new Presently I
am using a MCL PSC-3-1 to feed 3 receivers. I also got this at a hamfest.
My receivers make up the nearly 5 db loss.

How do they make up the loss? Just curious.

Maybe his radios have pre-amps like the Drakes.

When you use a passive splitter the loss is 3dB power and 6dB voltage. I
think most radio S meters are responding to the voltage number due to
the nature of the AGC circuits. Someone can correct me on this. Should
be easy enough to take a splitter in and out of line.

Correct me if I'm wrong... but would it not be better to run some
pre-amplification ahead of the splitter rather than try to make up something that
has already disappeared? Much the same in say VHF work where it is better to run a
receive pre-amp right at the antenna versus running it at the receiver end of the
coax?

I'd never consider using a passive splitter here, and I rarely if ever engage the
pre-amps on the receivers... no need.

dxAce
Michigan
USA


Most outboard amplifiers cause more problems than they solve. Listen
with your ears, not your S-Meter.

David wrote:

On Sun, 17 Apr 2005 18:06:44 -0400, dxAce
wrote:



Telamon wrote:

In article ,
dxAce wrote:

"Charles W. Hinkle" wrote:

I have used Mini Circut Labs ZFSC-2-1 and a 2 port passive Stridsberg. I
obtained the MCL's at hamfests for $10 and the Stridsberg new Presently I
am using a MCL PSC-3-1 to feed 3 receivers. I also got this at a hamfest.
My receivers make up the nearly 5 db loss.

How do they make up the loss? Just curious.

Maybe his radios have pre-amps like the Drakes.

When you use a passive splitter the loss is 3dB power and 6dB voltage. I
think most radio S meters are responding to the voltage number due to
the nature of the AGC circuits. Someone can correct me on this. Should
be easy enough to take a splitter in and out of line.

Correct me if I'm wrong... but would it not be better to run some
pre-amplification ahead of the splitter rather than try to make up something that
has already disappeared? Much the same in say VHF work where it is better to run a
receive pre-amp right at the antenna versus running it at the receiver end of the
coax?

I'd never consider using a passive splitter here, and I rarely if ever engage the
pre-amps on the receivers... no need.

dxAce
Michigan
USA


Most outboard amplifiers cause more problems than they solve. Listen
with your ears, not your S-Meter.

I don't use any outboard amplification here 'tard boy, other than that which the
Stridsberg uses to overcome the loss to support up to 4 receivers.

I'm fairly certain I've done my fair share of listening, you just keep on trying to
catch up.

Please, get a clue, and try to get a grip.

Continue to tote.

dxAce
Michigan
USA