Red Wave Radio

by **Shawn Reeve** » Mon, 02 Jul 2001 12:17:24

I'm considering placing a receiver at a site of another club, and am
wondering how much of a problem I'm going to run into. The site has a
repeater on 146.760, 100 watts or so.. we have a special receiver
that would (theoretically) work well at this site due to its height
and loction, but I fear there may be a problem. Our receiver is on
146.715. Is their repeater going to completly blow the socks off our
receiver? The receiver is just a "card receiver" that we took out of
an old MSR2000 repeater station. Their transmitter is a modified GE
MASTR II I believe.. it looks pretty clean, but still, its only 45 kHz
away.

Any comments? Am I nuts to even consider this?

by **Bob M** » Mon, 02 Jul 2001 20:56:25

As they say in New Yawk: "Fugetaboutit" Although you haven't said how far
away the transmitter is, I'm guessing you want to mount your antenna on the
same tower. With lots of notch filters you might eliminate the 146.76
signal, but you won't get anything through on 146.715 either. The first
thing you need is a lot of physical separation.

Bob M.
======

Quote:> I'm considering placing a receiver at a site of another club, and am
> wondering how much of a problem I'm going to run into. The site has a
> repeater on 146.760, 100 watts or so.. we have a special receiver
> that would (theoretically) work well at this site due to its height
> and loction, but I fear there may be a problem. Our receiver is on
> 146.715. Is their repeater going to completly blow the socks off our
> receiver? The receiver is just a "card receiver" that we took out of
> an old MSR2000 repeater station. Their transmitter is a modified GE
> MASTR II I believe.. it looks pretty clean, but still, its only 45 kHz
> away.

> Any comments? Am I nuts to even consider this?

by **Jim** » Tue, 03 Jul 2001 02:04:48

It will never work. Normally the repeater input is 600 Khz.
lower. Don't understand why you want to receive at the 146.715
frequency. If you mean to receive at the 146.115 frequency and
output at 146.715, then you may stand a chance. You will need to
notch out the other transmitter frequency of 146.76, just to be
able to even hear anything weak.

Jim

> I'm considering placing a receiver at a site of another club, and am
> wondering how much of a problem I'm going to run into. The site has a
> repeater on 146.760, 100 watts or so.. we have a special receiver
> that would (theoretically) work well at this site due to its height
> and loction, but I fear there may be a problem. Our receiver is on
> 146.715. Is their repeater going to completly blow the socks off our
> receiver? The receiver is just a "card receiver" that we took out of
> an old MSR2000 repeater station. Their transmitter is a modified GE
> MASTR II I believe.. it looks pretty clean, but still, its only 45 kHz
> away.

> Any comments? Am I nuts to even consider this?

by **John Adamso** » Tue, 03 Jul 2001 02:45:16

You may have to put a notch filter on 146.760 on the front end of your
receiver. If you can put vertical distance between the antennas that will

help. Remember, two mtr repeaters are only 600Khz xmit/rec freqs and
the filters required are intense.

Good luck, John w1hzh

ps: no ur not nuts but I would move the frequency a bit... :+)

> I'm considering placing a receiver at a site of another club, and am
> wondering how much of a problem I'm going to run into. The site has a
> repeater on 146.760, 100 watts or so.. we have a special receiver
> that would (theoretically) work well at this site due to its height
> and loction, but I fear there may be a problem. Our receiver is on
> 146.715. Is their repeater going to completly blow the socks off our
> receiver? The receiver is just a "card receiver" that we took out of
> an old MSR2000 repeater station. Their transmitter is a modified GE
> MASTR II I believe.. it looks pretty clean, but still, its only 45 kHz
> away.

> Any comments? Am I nuts to even consider this?

josttech.vcf
< 1K Download

by **Jim** » Tue, 03 Jul 2001 08:37:46

A notch filter will not work this close. You will also suck out
your own receive frequency. Notch filters are not sharp enough.
You may try a crystal filter, but it too may not work. You may
have too much power coming in and blow the crystal filter.

Jim

> You may have to put a notch filter on 146.760 on the front end of your
> receiver. If you can put vertical distance between the antennas that will

> help. Remember, two mtr repeaters are only 600Khz xmit/rec freqs and
> the filters required are intense.

> Good luck, John w1hzh

> ps: no ur not nuts but I would move the frequency a bit... :+)

> > I'm considering placing a receiver at a site of another club, and am
> > wondering how much of a problem I'm going to run into. The site has a
> > repeater on 146.760, 100 watts or so.. we have a special receiver
> > that would (theoretically) work well at this site due to its height
> > and loction, but I fear there may be a problem. Our receiver is on
> > 146.715. Is their repeater going to completly blow the socks off our
> > receiver? The receiver is just a "card receiver" that we took out of
> > an old MSR2000 repeater station. Their transmitter is a modified GE
> > MASTR II I believe.. it looks pretty clean, but still, its only 45 kHz
> > away.

> > Any comments? Am I nuts to even consider this?

by **Dan** » Tue, 03 Jul 2001 10:29:23

> > I'm considering placing a receiver at a site of another club, and am
> > wondering how much of a problem I'm going to run into. The site has a
> > repeater on 146.760, 100 watts or so.. we have a special receiver
> > that would (theoretically) work well at this site due to its height
> > and loction, but I fear there may be a problem. Our receiver is on
> > 146.715. Is their repeater going to completly blow the socks off our
> > receiver? The receiver is just a "card receiver" that we took out of
> > an old MSR2000 repeater station. Their transmitter is a modified GE
> > MASTR II I believe.. it looks pretty clean, but still, its only 45 kHz
> > away.

> > Any comments? Am I nuts to even consider this?

What I want to know is why that club needs a repeater with so much power?
Nothing like being able to hear a repeater a 100+ miles away and not being
able to get into it.

With less power a crystal filter might work, but 100 watts...

Dan
N7SLC

by **Ralph Mower** » Tue, 03 Jul 2001 11:23:16

With many of the moble rigs running around 50 watts now, a 100 watt
repeater is not much overkill. With some noise near the moble receiver
the effective sensitivity can be less than the repeater receiver.
There are some repeaters that don;t cater to the HT hams and their 5
watts or less.

Quote:
> What I want to know is why that club needs a repeater with so much power?
> Nothing like being able to hear a repeater a 100+ miles away and not being
> able to get into it.

> With less power a crystal filter might work, but 100 watts...

> Dan
> N7SLC

by **rshpr** » Wed, 04 Jul 2001 12:09:43

At 45KHz between your RX and their TX, you are not going to be able to
filter enough to have any real useful sensitivity from your RX. Filter
technology is not that good, and even if it were, it would exceed reasonable
cost.
Personally, I would find another site.

Quote:> I'm considering placing a receiver at a site of another club, and am
> wondering how much of a problem I'm going to run into. The site has a
> repeater on 146.760, 100 watts or so.. we have a special receiver
> that would (theoretically) work well at this site due to its height
> and loction, but I fear there may be a problem. Our receiver is on
> 146.715. Is their repeater going to completly blow the socks off our
> receiver? The receiver is just a "card receiver" that we took out of
> an old MSR2000 repeater station. Their transmitter is a modified GE
> MASTR II I believe.. it looks pretty clean, but still, its only 45 kHz
> away.

> Any comments? Am I nuts to even consider this?

by **Pete Gianakopoulo** » Tue, 10 Jul 2001 12:23:54

Your separation will not be 45KHz, but 555KHz. You will need a duplexer
that has its notch filter set for 146.160MHz; this will provide the required
attenuation of the transmitter. You won't have the physical isolation of a
remote location, but it is worth a try.

Pete

> At 45KHz between your RX and their TX, you are not going to be able to
> filter enough to have any real useful sensitivity from your RX. Filter
> technology is not that good, and even if it were, it would exceed
reasonable
> cost.
> Personally, I would find another site.

> > I'm considering placing a receiver at a site of another club, and am
> > wondering how much of a problem I'm going to run into. The site has a
> > repeater on 146.760, 100 watts or so.. we have a special receiver
> > that would (theoretically) work well at this site due to its height
> > and loction, but I fear there may be a problem. Our receiver is on
> > 146.715. Is their repeater going to completly blow the socks off our
> > receiver? The receiver is just a "card receiver" that we took out of
> > an old MSR2000 repeater station. Their transmitter is a modified GE
> > MASTR II I believe.. it looks pretty clean, but still, its only 45 kHz
> > away.

> > Any comments? Am I nuts to even consider this?

by **rshpr** » Tue, 10 Jul 2001 21:23:03

Pete,

Shawn Stated:
********************************
"The site has a repeater on 146.760, 100 watts or so.. we have a special
receiver that would (theoretically) work well at this site due to its height
and location, but I fear there may be a problem. Our receiver is on
146.715."

146.7600 TX - 147.715 RX = 0.045 MHz or 45KHz Separation between TX and RX.
********************************
Assuming Shawn has stated the problem correctly (TX/RX assignments), that
would place his system transmitter at 146.1150 MHz (clearly an oddball,
inverted split).

However, I would agree it appears at least, that Shawn actually (hopefully)
has his numbers backwards and that his system TX is actually 146.7150 MHz
and RX at 146.1150 MHz, which is as you stated, not really a problem. This
is because he would then have 0.645 MHz or 645 KHz between his RX 146.115
MHz and their TX at 146.7600 MHz.

The problem "as stated", is a bad one with only 45 KHz between TX and RX.

73,
Bob-KA9FLX

> Your separation will not be 45KHz, but 555KHz. You will need a duplexer
> that has its notch filter set for 146.160MHz; this will provide the
required
> attenuation of the transmitter. You won't have the physical isolation of
a
> remote location, but it is worth a try.

> Pete

> > At 45KHz between your RX and their TX, you are not going to be able to
> > filter enough to have any real useful sensitivity from your RX. Filter
> > technology is not that good, and even if it were, it would exceed
> reasonable
> > cost.
> > Personally, I would find another site.

> > > I'm considering placing a receiver at a site of another club, and am
> > > wondering how much of a problem I'm going to run into. The site has a
> > > repeater on 146.760, 100 watts or so.. we have a special receiver
> > > that would (theoretically) work well at this site due to its height
> > > and loction, but I fear there may be a problem. Our receiver is on
> > > 146.715. Is their repeater going to completly blow the socks off our
> > > receiver? The receiver is just a "card receiver" that we took out of
> > > an old MSR2000 repeater station. Their transmitter is a modified GE
> > > MASTR II I believe.. it looks pretty clean, but still, its only 45 kHz
> > > away.

> > > Any comments? Am I nuts to even consider this?

by **rshpr** » Wed, 11 Jul 2001 01:07:10

Sorry,
The rest of the number are correct, but it is
146.7600 TX - 146.715 RX = 0.045 MHz or 45KHz Separation between TX and RX.
Minor typo, but big math problem. :-)
Calculation is correct with the right numbers.

Bob-KA9FLX:

> Pete,

> Shawn Stated:
> ********************************
> "The site has a repeater on 146.760, 100 watts or so.. we have a special
> receiver that would (theoretically) work well at this site due to its
height
> and location, but I fear there may be a problem. Our receiver is on
> 146.715."

> 146.7600 TX - 147.715 RX = 0.045 MHz or 45KHz Separation between TX and
RX.
> ********************************
> Assuming Shawn has stated the problem correctly (TX/RX assignments), that
> would place his system transmitter at 146.1150 MHz (clearly an oddball,
> inverted split).

> However, I would agree it appears at least, that Shawn actually
(hopefully)
> has his numbers backwards and that his system TX is actually 146.7150 MHz
> and RX at 146.1150 MHz, which is as you stated, not really a problem.
This
> is because he would then have 0.645 MHz or 645 KHz between his RX 146.115
> MHz and their TX at 146.7600 MHz.

> The problem "as stated", is a bad one with only 45 KHz between TX and RX.

> 73,
> Bob-KA9FLX

> > Your separation will not be 45KHz, but 555KHz. You will need a duplexer
> > that has its notch filter set for 146.160MHz; this will provide the
> required
> > attenuation of the transmitter. You won't have the physical isolation
of
> a
> > remote location, but it is worth a try.

> > Pete

> > > At 45KHz between your RX and their TX, you are not going to be able to
> > > filter enough to have any real useful sensitivity from your RX.
Filter
> > > technology is not that good, and even if it were, it would exceed
> > reasonable
> > > cost.
> > > Personally, I would find another site.

> > > > I'm considering placing a receiver at a site of another club, and am
> > > > wondering how much of a problem I'm going to run into. The site has
a
> > > > repeater on 146.760, 100 watts or so.. we have a special receiver
> > > > that would (theoretically) work well at this site due to its height
> > > > and loction, but I fear there may be a problem. Our receiver is on
> > > > 146.715. Is their repeater going to completly blow the socks off
our
> > > > receiver? The receiver is just a "card receiver" that we took out
of
> > > > an old MSR2000 repeater station. Their transmitter is a modified GE
> > > > MASTR II I believe.. it looks pretty clean, but still, its only 45
kHz
> > > > away.

> > > > Any comments? Am I nuts to even consider this?

Red Wave Radio

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Repeater freq near receiver freq?

Repeater freq near receiver freq?

Repeater freq near receiver freq?

Repeater freq near receiver freq?

Repeater freq near receiver freq?

Repeater freq near receiver freq?

Repeater freq near receiver freq?

Repeater freq near receiver freq?