In Texas the JCAH (Joint Commission on Accreditation of Hospitals)
guidelines forbids installation and operation of radio transmitting
equipment in hospital elevator equipment rooms. Both Scott and White
and Kings Daughters Hospitals had us re-locate all of their radio
equipment in the early
I remember one such room back in the mid to late
1970s; actually it was almost a floor in itself, as
opposed to a room. Four huge Westinghouse traction
motors, each with its own rotary converter, handled 11
floors. Racks with hundreds of microswitches and a
moving panel followed the cab's progress
Any suggestions on what to use for a jumper between the
Heliax and the antenna for the last few feet to provide
flexability and make it easier to get the cable into the
antenna mount?
Thanks,
Vern
[EMAIL PROTECTED] wrote:
Any suggestions on what to use for a jumper between the
Heliax and the antenna for the last few feet to provide
flexability and make it easier to get the cable into the
antenna mount?
RG-214
Dex
Code is one thing. At the end of the code it states Or as local
authority dictates Which translates to what ever the local inspector
(aka, self proclaimed god) believes to be the correct interpretation of
the code.
A few years ago at the Ford World Head Quarters building in Dearborn
Hmmm...Sounds like we need to get the elevator buyers to make the bid specs
include a VHF radio in each elevator car!
73 - Paul AE4KR
- Original Message -
From: Eric Lemmon
To: Repeater-Builder@yahoogroups.com
Sent: Wednesday, October 31, 2007 7:52 PM
Subject:
Guys, thanks for the suggestions.
The duplexer manufacturer websites have scant info. TX-RX Systems has two
graphs, one for VHF high band, one for UHF, but no info on the assumptions
behind the math.
I'm skeptical about the usefulness of receiver adjacent-channel rejection
specs, for two
Anyone have a manual for the DTMF controller?
Thanks, Jim
Eric Lemmon [EMAIL PROTECTED] wrote:
I won't presume to know what prompts some people to ignore the
law and/or common sense in these cases.
Simple, pressure from the gobal economy and what I term the
Wal Mart effect.
s.
There is no magic formula. The curves given by the duplexer manufacturers
are typical for radios like Motorola and GE.
Duplexer isolation requirements have little if anything to do with adjacent
channel receiver selectivity. That number only tells you how strong the
neighboring frequency can
Anyone got a scanned or photocopy of the famous PC-Board Duplexer
QST Magazine Article from years past... they could/would share?
This is the duplexer kit made sold by Circuit Board Specialists
in Pueble CO.
thanks in advance for your replies
s.
George,
To my knowledge there was no grandfather period awarded. My 900 repeater
is located in the penthouse of a 19-floor geriatrics housing building in
Joliet, and they made us move all transmitters out of the elevator equipment
room about 2 years ago, including the Sheriff, Joliet PD and FD,
Hi Don,
The quick answer is no yes no. The long answer is,
On the low band Compa-Station the output power control Board samples
the VSWR on the output and folds back, the gain of the pre-driver in
the power amplifier when the VSWR gets too high compared to the current
draw of the final
Actually, it is addressed in NFPA 70- the National Electrical Code- which
is
ratified by each State's legislature as law in that State. I quote NFPA
70-2005 Article 620.37, Wiring in Hoistways, Machine Rooms, Control Rooms,
Machinery Spaces, and Control Spaces in its entirety:
(A) Uses
Gary,
I appreciate the comments, and agree with all but one. If transmitter sideband
noise, filter skirts and dynamic range can all be represented by numbers, then
they should be able to be distilled down to a formula. A complicated one, to be
sure, but nothing magic. Those
According to the ARRL web site QST index search, it was April 1979, page 11. I
don't have that one, but do have a copy of the 1972 6-can duplexer construction
article.
Somebody out there must have the QST CD-ROM that covers 1979, though
George, KA3HSW / WQGJ413
-Original
Years ago the standard scanner radio antenna
connector was the so-called Motorola car radio
connector. It was a metal cylinder maybe 1/4 in
diameter with a protruding center pin.
Does anybody know of a commercial source of
a male Motorola connector to BNC female adapter?
Alternatively an SO239
Hi Paul,
I meant that it was not complicated to figure out.
For example if the receiver noise floor (sensitivity) is -120 dbm then the
transmitter noise power must be known at the receive frequency (as supplied
from the manufacturer or measured) and an amount of attenuation added at the
Is this what you're looking for:
http://www.scannerworld.com/content/product/model/ANT38
Bob M.
==
--- Mike Morris WA6ILQ [EMAIL PROTECTED] wrote:
Years ago the standard scanner radio antenna
connector was the so-called Motorola car radio
connector. It was a metal cylinder maybe 1/4 in
If it will help any, I bought one at Radio Shack a few years ago.
Johnny
Mike Morris WA6ILQ wrote:
Years ago the standard scanner radio antenna
connector was the so-called Motorola car radio
connector. It was a metal cylinder maybe 1/4 in
diameter with a protruding center pin.
Does
Hello all,
Reference RBTIP MASTR II websites:
http://www.repeater-builder.com/
http://www.mastr2.com/
Everyone knows I hate asking for financial support, but it's the only
way I can afford to keep the Repeater Builder site up and running
reliably. I have been ask why don't you consider a
At 01:32 PM 11/01/07, you wrote:
According to the ARRL web site QST index search, it was April 1979,
page 11. I don't have that one, but do have a copy of the 1972
6-can duplexer construction article.
Somebody out there must have the QST CD-ROM that covers 1979, though
George, KA3HSW /
On Thu, 1 Nov 2007, Mike Morris WA6ILQ wrote:
Years ago the standard scanner radio antenna connector was the
so-called Motorola car radio connector. It was a metal cylinder
maybe 1/4 in diameter with a protruding center pin.
Yes, I could butcher the radio and install a BNC female, but I
last ones I got from radio shack. They may still have some if you can get
the salesman to stop trying to sell you a cell phone long enough!
Mike KA2NDW
-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] Behalf Of Mike Morris WA6ILQ
Sent: Thursday,
EXACTLY !!!
They are closed now, I'll call them tomorrow and get two into the mail...
Thanks!
Mike WA6ILQ
At 03:08 PM 11/01/07, you wrote:
Is this what you're looking for:
http://www.scannerworld.com/content/product/model/ANT38
Bob M.
==
--- Mike Morris WA6ILQ [EMAIL PROTECTED] wrote:
I have 65w out of the duplexer on 2m. A friend has a
rg214 jumper for me so I think I will use it.
On Thu, 01 Nov 2007 13:14:00 -0700
Mike Morris WA6ILQ [EMAIL PROTECTED] wrote:
At 07:01 AM 11/01/07, you wrote:
Any suggestions on what to use for a jumper between the
Heliax and the antenna
At 07:01 AM 11/01/07, you wrote:
Any suggestions on what to use for a jumper between the
Heliax and the antenna for the last few feet to provide
flexability and make it easier to get the cable into the
antenna mount?
Thanks,
Vern
What's the power level?
At 100w or less I use RG-400.
At higher
Mike,
Go to your neighborhood Radio Shack emporium and ask for a #278-208
UHF-to-Motorola-Type Scanner Adapter. It'll set you back $3.49- if it is
in stock. It is a male Motorola antenna plug on one end, and a SO-239 jack
on the other.
73, Eric Lemmon WB6FLY
-Original Message-
From:
Paul,
General Electric published several Datafile Bulletins which will help you.
Here's one:
www.repeater-builder.com/ge/datafile-bulletin/df-10003-01.pdf
Since you already have experience with Mastr II radios, you'll appreciate
that the Duplex Operation Curves are available on the GE Master
Jim,
Have you had the cover off of it? I think I had one of those. There was
basic jumper programming for touch tones and connection info on the inside
of the top cover.
73,
Gerald Pelnar WD0FYF
McPherson, Ks
- Original Message -
From: K7OET [EMAIL PROTECTED]
To:
I'll scan the Dec. 2005 article tomorrow and send you both.
George
- Original Message -
From: Mike Morris WA6ILQ [EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Sent: Thursday, November 01, 2007 4:24 PM
Subject: Re: [Repeater-Builder] pc board duplexer article
At 01:32 PM
Dump a copy of the duplexer article this way if you would. I need something
better than the 4-6 cans I currently have.
_
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of George Henry
Sent: Thursday, November 01, 2007 11:11 PM
To:
The major problem I was having is resolved. I've finally got a UHF backyard
pair for my portable repeater :-) No more hassling with trying to pack 4
radios into 1mhz of VHF bandwidth :-)
Since there isn't a way to look at receiver specs and figure how much
isolation is really needed, here I am
On Nov 1, 2007, at 10:16 PM, John Barrett wrote:
Since there isn’t a way to look at receiver specs and figure how
much isolation is really needed, here I am asking – what is my best
bet for radios to build a UHF repeater? I’m currently looking at a
Hamtronics receiver/exciter pair with
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