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

dxAce wrote:
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
------------------------------
The results might surprise you.
When I received my zfsc-2-1 I expected the addional ~3.5dB loss to be
an
issue. But after much testing I found that it didn't make that much
difference.
For the most part any signal I could receive without the addtional loss
was
still present with the loss. I used a HP step atenuator to check this
before going to the trouble of mounting the zfsc.

I really expected to need a good low noise, high intercept, preamp
before
the splitter. If you have a "good enough" antenna the additional loss
is of slight concern.

Since I have all of my antennas, receivers, RF filters on a patch
panel,
it allows me to easily move the splitter out of line. I use BNC
connectors
because I was given a "boat load" of them and find them easier and
faster to move then PL/SO-259 connectors.

A friend wanted a similar setup and I gave him enough bulkhead mount
"F" femalefemale to allow him to bring all of his antenas and both
receivers to a panel. He found an "old" TV spliter that works very well
to below the MW/BCB band. I bought a bag of over 500 for $1 at the
local Goodwill store.

Another advantage of a RF patch panel is I can connect my Pro2004 IF
out to my R2000 so I can listen to SSB VHF/UFF comms.

I do have to be very carefull to insure that I don't connect my ham
gear to
my receiver inputs. At them moment I have them feeding different RF
patch
panels and simply don't ever connect my ham gear to a receive antenna.
I am considering switching all of my receive RF connectors to "F", at
least
at the patch panel. I have thought of using TNC but they are expensive
and are easier to crossthread then "F".

Terry

wrote:

dxAce wrote:
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
------------------------------
The results might surprise you.

The results of what? Using a passive splitter?


When I received my zfsc-2-1 I expected the addional ~3.5dB loss to be
an
issue. But after much testing I found that it didn't make that much
difference.
For the most part any signal I could receive without the addtional loss
was
still present with the loss. I used a HP step atenuator to check this
before going to the trouble of mounting the zfsc.

I really expected to need a good low noise, high intercept, preamp
before
the splitter. If you have a "good enough" antenna the additional loss
is of slight concern.

But it is still a loss, is it not?

Since I have all of my antennas, receivers, RF filters on a patch
panel,
it allows me to easily move the splitter out of line. I use BNC
connectors
because I was given a "boat load" of them and find them easier and
faster to move then PL/SO-259 connectors.

A friend wanted a similar setup and I gave him enough bulkhead mount
"F" femalefemale to allow him to bring all of his antenas and both
receivers to a panel. He found an "old" TV spliter that works very well
to below the MW/BCB band. I bought a bag of over 500 for $1 at the
local Goodwill store.

Another advantage of a RF patch panel is I can connect my Pro2004 IF
out to my R2000 so I can listen to SSB VHF/UFF comms.

I do have to be very carefull to insure that I don't connect my ham
gear to
my receiver inputs. At them moment I have them feeding different RF
patch
panels and simply don't ever connect my ham gear to a receive antenna.
I am considering switching all of my receive RF connectors to "F", at
least
at the patch panel. I have thought of using TNC but they are expensive
and are easier to crossthread then "F".

You've made no pertinent point.

dxAce
Michigan
USA

BNCs are certainly the way to go as opposed to PL-259

If you keep your eyes open, you can get real RF patch bays. I don't
know the name of the connector, but they are really patches, i.e. no
threads. About the only way to buy these RF patch bays is with the
patches at the same time. There seem to be two similar designs, but the
dimensions are not quite the same. I ohmed out all the connectors
before buying any of the patch cables. The whole deal about about $30
to $40 a few years ago. Mine had the stickers on from a radar company
(Whistler), so I'm pretty sure it was 50 ohm. I guess there is a risk
you might get a 75 ohm video patch bay.

Unless the pre-amp is as clean as your radio, I'd take the loss in the
splitter and make it up in the AGC. I wouldn't want to risk intermod in
the amp degrading the reception of the signal.

Signal strength and quality of the signal are not always related. You
can experiment by taking a strong signal and pad it down with an
antennuator to the level of some weak signal. The padded down strong
signal tends to sound cleaner. I think this is because the pad also
reduced the level of the background noise at the same time, while a
weak signal has a lower signal to noise ratio "naturally." I hope that
makes sense.

wrote:

BNCs are certainly the way to go as opposed to PL-259

If you keep your eyes open, you can get real RF patch bays. I don't
know the name of the connector, but they are really patches, i.e. no
threads. About the only way to buy these RF patch bays is with the
patches at the same time. There seem to be two similar designs, but the
dimensions are not quite the same. I ohmed out all the connectors
before buying any of the patch cables. The whole deal about about $30
to $40 a few years ago. Mine had the stickers on from a radar company
(Whistler), so I'm pretty sure it was 50 ohm. I guess there is a risk
you might get a 75 ohm video patch bay.

Unless the pre-amp is as clean as your radio, I'd take the loss in the
splitter and make it up in the AGC. I wouldn't want to risk intermod in
the amp degrading the reception of the signal.

Signal strength and quality of the signal are not always related. You
can experiment by taking a strong signal and pad it down with an
antennuator to the level of some weak signal. The padded down strong
signal tends to sound cleaner. I think this is because the pad also
reduced the level of the background noise at the same time, while a
weak signal has a lower signal to noise ratio "naturally." I hope that
makes sense.


http://www.switchcraft.com/products/vpp.html &
http://www.switchcraft.com/products/561.html are examples of video patch
bays and plugs that work for HF receivers as well. They are used for
manual routing of video in some studios and transmitter sites. Western
Electric used to use them on their coaxial long lines that fed video
cross country before TV satellites were available. If you're old enough
to remember the nationwide live video feed after President Kennedy was
assassinated, the techs and engineers at ATT patched together the first
nationwide feed by connecting the different network's feeds together to
provide all network stations with live video and did the same with the
audio feeds.


--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

On Mon, 18 Apr 2005 02:43:05 GMT, "Michael A. Terrell"
wrote:


http://www.switchcraft.com/products/vpp.html &
http://www.switchcraft.com/products/561.html are examples of video patch
bays and plugs that work for HF receivers as well. They are used for
manual routing of video in some studios and transmitter sites. Western
Electric used to use them on their coaxial long lines that fed video
cross country before TV satellites were available. If you're old enough
to remember the nationwide live video feed after President Kennedy was
assassinated, the techs and engineers at ATT patched together the first
nationwide feed by connecting the different network's feeds together to
provide all network stations with live video and did the same with the
audio feeds.
75 Ohms, if that matters.

If you're going to use RG-59/U, you might as well just use
ubiquitous and cheap F-Connectors and A/B/C switches.

David wrote:

On Mon, 18 Apr 2005 02:43:05 GMT, "Michael A. Terrell"
wrote:

http://www.switchcraft.com/products/vpp.html &
http://www.switchcraft.com/products/561.html are examples of video patch
bays and plugs that work for HF receivers as well. They are used for
manual routing of video in some studios and transmitter sites. Western
Electric used to use them on their coaxial long lines that fed video
cross country before TV satellites were available. If you're old enough
to remember the nationwide live video feed after President Kennedy was
assassinated, the techs and engineers at ATT patched together the first
nationwide feed by connecting the different network's feeds together to
provide all network stations with live video and did the same with the
audio feeds.
75 Ohms, if that matters.

If you're going to use RG-59/U, you might as well just use
ubiquitous and cheap F-Connectors and A/B/C switches.


If you want to use 75 ohm cables its your choice. The patch bays are
BNC on both halves so you can use 50 or 75 ohm cables with them. These
patch bays show up used and surplus along with the plugs. I've used
them at several TV stations, a mobile production van I built and in the
telemetry package we shipped to Italy. They are a lot better quality
than "F" fittings and CATV switches. I used to run insertion loss and
other tests on samples for United Video Cablevision and there was more
junk submitted than quality parts. Even the better quality switches
only lasted a year or so when we used them to reroute video feeds in the
L.O. studio.

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

On Mon, 18 Apr 2005 13:33:03 GMT, "Michael A. Terrell"
wrote:



If you want to use 75 ohm cables its your choice. The patch bays are
BNC on both halves so you can use 50 or 75 ohm cables with them. These
patch bays show up used and surplus along with the plugs. I've used
them at several TV stations, a mobile production van I built and in the
telemetry package we shipped to Italy. They are a lot better quality
than "F" fittings and CATV switches. I used to run insertion loss and
other tests on samples for United Video Cablevision and there was more
junk submitted than quality parts. Even the better quality switches
only lasted a year or so when we used them to reroute video feeds in the
L.O. studio.

75 Ohm BNCs and 50 Ohm BNCs are two different connectors. You can mix
them up if you like, but it's lame.