Hello all from down under! I have a Motorola power supply that has come out of
a repeater installation and I am looking for some info on it. What I am mostly
wanting to know is what a small row of header type pins are for - external
meters etc perhaps? The numbers on the transformer are -
Hi Graham,
We recently threw out dozens of similar items from Transpower sites that were
in service as constant voltage float chargers in substations.
What you may have is a constant voltage charger with supervision circuitry by
the looks of it, and a way to set voltage and overcurrent
Had a similiar situation at our site, a station on 106.7 MHz, music on hang
time on many repeaters, intermod runs gave no clue to reason, did all the
usual, grounding, filters no resolve.
Turned out to be the STL Marti system on 450.100 MHz, from an close studio site
pointed right at our site,
A lot of strange things can happen.
We had a situation where a school bus control station that was situated a
couple blocks from an FM broadcast tower caused the control station to spur
and get into our control station almost 20 miles away. When the offending
control station was put on the
Think about it this way. If you made a dipole, would you
cut one side 5% longer than the other?
Maybe, if you had a reason for offset feed... but most offset
Dipoles are not 5% different. I thought the subject was about
1/4 wave ground planes and not dipoles... they are not the
same
Hi Folks,
I'm working on a low band Micor, and only have
some K1005A channel elements. (they are the 'vhf'
elements... the 1003 are the 'low band').
I've looked at the schematic to the 1005 here on RB
versus what I see in the 1005, and with the exception
of a resistor, and possibly the
On Mon, 22 Feb 2010, Jeff DePolo wrote:
Kinda along the same lines as always make the cable from the
connector on the transmitter to the connector on the duplexer an even
half-wave.
The reason for doing that is that if the duplexer presents a
short-circuit, said short-circuit won't appear
In the commercial world of broadcasting, there is a hybrid filter used
called a mask filter. The mask filter is two -90 degree hybrids, a dummy
load, and a pair of bandpass cavities between them. They suppress
sidebands and keep the TV transmitter's radiation within the 6MHz
channel.
Has
Recently bought a Daniels low band base station on eBay. A friend of mine and I
were able to get it working on the low end of 6 meters without any component
changes.
I'll report back on how that goes when it happens.
In the meantime, I am in search of the following parts for Daniels
I placed the following post regarding a pair of 220 MHz duplexers and received
a few interest messages, but after the initial messages, there was no follow
up.
I need to get rid of these items, so I am reposting the message with the
following deadline.
I will accept the best offer PLUS
I have a number of repeaters for sale in different fequency bands. I am
looking to sell them either whole or as individual parts to anyone interested.
Please contact me OFFLINE with individual questions. Freq data is as follows:
Micor repeatersin the 450, 470 and 800 Bands
MSF5000 900 Band
I'd be intrested in one or both of the duplexers, would you take $50
and $20 shipping each?
On Mon, Feb 22, 2010 at 11:50 AM, bbfmrf bbf...@yahoo.com wrote:
I placed the following post regarding a pair of 220 MHz duplexers and
received a few interest messages, but after the initial messages,
On Mon, 22 Feb 2010, Jeff DePolo wrote:
Kinda along the same lines as always make the cable from the
connector on the transmitter to the connector on the
duplexer an even
half-wave.
The reason for doing that is that if the duplexer presents a
short-circuit, said short-circuit won't
Kris,
These filters are constant impedance designs so the transmitters unwanted
sideband power gets dumped into a load on the Hybrid port. This also helps
with group delay at edges of the filtered response.
... cant see why a ham would make a filter with twice as many cavities than
needed, just
It's Bacon!
That's my point. If there was a specific reason for
making one side of the dipole exactly 5% longer (based on
some pre-determination such as a computer model), then fine.
I was talking about 1/4 wave ground plane antennas with 90
degree horizontal radiators... not
I suspect you're operating down in the lower 51/52 MHz
portion of the band and that you're limited to programming
the assigned frequency to 20KHz Steps?
Congrads on the successful conversion...
s.
--- In Repeater-Builder@yahoogroups.com, surf_boy82 surf_bo...@... wrote:
Recently bought a
Skipp
I sure would be interested in what your version of a beta matched gnd plane
antenna which results in a 50 Ohm match looks like.
Could you, would you, provide us with a description or picture to satisfy my
curiosity?
Thanks,
a.
--- On Mon, 2/22/10, skipp025 skipp...@yahoo.com wrote:
On Mon, 22 Feb 2010, IM Ashford wrote:
These filters are constant impedance designs so the transmitters
unwanted sideband power gets dumped into a load on the Hybrid port.
This also helps with group delay at edges of the filtered response.
... cant see why a ham would make a filter with
On Mon, 22 Feb 2010, Jeff DePolo wrote:
On Mon, 22 Feb 2010, Jeff DePolo wrote:
Kinda along the same lines as always make the cable from the
connector on the transmitter to the connector on the
duplexer an even
half-wave.
The reason for doing that is that if the duplexer
allan crites wa9...@... wrote:
Skipp
I sure would be interested in what your version of a beta
matched gnd plane antenna which results in a 50 Ohm match
looks like.
It looks just like a standard 1/4 ground plane, single vertical
radiator, three (typical) horizontal elements
-Original Message-
From: Repeater-Builder@yahoogroups.com [mailto:Repeater-
buil...@yahoogroups.com] On Behalf Of Kris Kirby
Sent: Monday, February 22, 2010 5:03 PM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Re: DB-201 Measurements for 6 Meters?
On Mon,
Would you consider the 1/8 rod to be a 1/4 WL stub? Or is it some arbitrary XL
to cancel the XC of the shorter than resonance 1/4 WL radiator (not considering
the benefit of having a DC gnd for the vertical radiator).
I am interested in knowing how this rod makes a gnd plane antenna which has
Tim,
It is the policy at International Crystal that you can send them a working
channel element that is similar to the model you need, and they will crystal
and compensate the exact element you need- if one is in their surplus stock.
Call ICM first to see if they have the element in stock. I
I know of one amateur repeater where a distant AM broadcast signal mixed
with a commercial Tx operating on the same tower to produce interference on
the repeater input.
The problem was tracked to a rust joint between the galvanised iron roof and
the guttering of the equipment hut.
The broadcast
Skipp, I wonder if the antenna you stole this idea from was the Hy-Gain GPG-1
high band ground plane antenna we used to use in the late '60s and early '70s.
The dc ground was a real feature of this simple antenna.
Sure wish I could remember how they connected the feedline to this antenna. I
Hello,
This email message is a notification to let you know that
a file has been uploaded to the Files area of the Repeater-Builder
group.
File: /DB-201 Assembly and Install.pdf
Uploaded by : e9tech weja...@charter.net
Description : DB-201 Assembly and Installation Guide
You
Hello,
This email message is a notification to let you know that
a file has been uploaded to the Files area of the Repeater-Builder
group.
File: /DB-201 Cutting Chart.pdf
Uploaded by : e9tech weja...@charter.net
Description : DB-201 Cutting Chart
You can access this file at
The straight skinny about the beta or hairpin match can be found in
a QST article, April 1962, by Gooch and Gardiner. It explains how this
matching scheme works. The driven element is shortened making it capacitive.
Then the inductive reactance of the hairpin or beta section re-resonates
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