In circular polarization you will find that half the power goes into
the vertical polarization and half goes into the horizontal, thereby
having a gain of -3db (for one element). CP is why you
rarely,
but rarely have any hot spots or hear any mobile flutter on
the
FM broadcast band. You
If we were talking about 6-meters, I'd agree on the 6-dB disadvantage in
the mobile environment. I've never seen anything like that on UHF. I
don't buy into this argument yet ;-)
Chuck
WB2EDV
[EMAIL PROTECTED] wrote:
Well, with a good preamp at a quiet site, usable sensitivity on a UHF
On Sat, 11 Feb 2006, Mike Morris wrote:
More details at http://wa6tdd.tripod.com and it's really worth
reading. And wait for the photos to load - they are worth it as well
(just for the photo of WA6ITF 40 years ago). The Jampro story is just
under his picture.
That was an astounding
Monday, I am having this antenna put up on a
triangular tower, whose face is greater than 20 ft. across where the antenna is
going on one leg. I know from years of operationon this tower (or any
tower that is this large), the antenna patternwill have manynulls
around the tower. Does
Wow~ solid, broadband, heated... the stuff dreams are made of g
Yeah, I'm jealous. ~/ N8BQN /~
Mike Morris wrote:
In this particular case the antenna was .. rebuilt to 146Mhz by Jampro
as a favor to 'OQK (who is a professional broadcast engineer).
serious snipage
Yahoo! Groups
Steve Hutzley wrote:
I am checking my local contacts for some elements,
when I do come across some, and I want to have them
re-crystaled, what exactly whould I ask for/tell the
manufacturer to do to make sure it is compatible for
use in an amatuer FM repeater, besides its for a Micor
station, it
N9WYS wrote:
While we're on this subject -- can I use an element from a VHF-Lo Micor and
have it recrystaled to a UHF freq?
No.
Unlike GE Mastr II, Motorola Micor elements are different between bands.
Kevin
Yahoo! Groups Links
* To visit your group on the web, go to:
Just a public Thank You for your efforts
Kevin Custer
[EMAIL PROTECTED] wrote:
All I ask in
return is for you to donate to the upkeep and availability of the Repeater-Builder
site.
Honor
System
Let you conscience be your guide.
The Donate
Yes but that sounds sort of risky in that the lowest noise
figure of an LNA
is not necessarily achieved at optimum match.
Agreed, and most are tuned for lowest NF and not necessarily maximum gain
nor ideal match.
My previous comments relating to LNAs may also apply to the
JFET mixers
If we were talking about 6-meters, I'd agree on the 6-dB
disadvantage in
the mobile environment. I've never seen anything like that on UHF. I
don't buy into this argument yet ;-)
Chuck
WB2EDV
OK, if you don't like the mobile noise environment model, let's just look at
raw sensitivity
On Sat, 11 Feb 2006, Mike Morris wrote:
More details at http://wa6tdd.tripod.com and it's really worth
reading. And wait for the photos to load - they are worth
it as well
(just for the photo of WA6ITF 40 years ago). The Jampro
story is just
under his picture.
That was an
I seem that it is very diffacult to keep track of Lightning (AKA Mike
M). But Lightning seems to strike once in a while!!!
Will from the hill, OK back to fixing Spectras...
Ronny Julian [EMAIL PROTECTED] wrote:
Another one heard from. Will the bashings ever cease?
- Original Message
Rodger,
I have a DB-228 that is mounted in
the center of the Northwest face. The faces are 8 across if memory
serves me correctly. We are at 635 Center of Radiation and only running 12.5
watts in to the cavities but we are getting 45 50 mile radius coverage from
the repeater. I have
The existing mount exact size I do not know, but it
is at least 3feet off the leg (and offset to make the antenna vertical,
since the tower (450 ft. self supporting)slopes slightly). I have had a
Sinclair co-linear(6 dB) up at this height a number of years ago and it
seemed to have a
Jeff DePolo wrote:
If we were talking about 6-meters, I'd agree on the 6-dB
disadvantage in
the mobile environment. I've never seen anything like that on UHF. I
don't buy into this argument yet ;-)
Chuck
WB2EDV
OK, if you don't like the mobile noise environment model, let's just look
Hi Guys:
I just came across a neat little heatsink that is fan
forced from one end. It was originally used in an RCA
model RT2380BK surround sound amplifier, which had an
output of about 200 watts.
It turns out that this amplifier has a very common problem
with the LSI (large scale integration)
More details at http://wa6tdd.tripod.com and it's really
worth reading. And wait for the photos to load - they are
worth it as well (just for the photo of WA6ITF 40 years
ago). The Jampro story is just under his picture.
I think he would have been WA2HVK at that time. Although his 6 land call
But, any 3 dB TX ERP loss is accompanied by a 3 dB RX loss as well. As I
said before, any antenna gains or feedline losses cancel out when it
comes to TX vs RX ability.
Joe M.
Yahoo! Groups Links
* To visit your group on the web, go to:
http://groups.yahoo.com/group/Repeater-Builder/
Good Afternoon,
I have a Sinclair Model 202G duplexer in which one of the insertion
loops has a bad (cracked) piston capacitor. Has anyone had occasion
to replace one of these and if so what did you replace it with? I can
measure the size of the one that is there but without knowing the
Jeff DePolo wrote:
Would you not agree that a good UHF repeater receiver with a GaAsFET ahead of it
will have better sensitivity than a typical mobile radio? If so, by what amount?
Chuck Kelsey wrote:
No. A "typical" UHF ham rig will have better sensitivity than most
For what its worth - and since this
thread started because of my mention of the 150W transmitter I should
note that the RX sensitivity on the Kenwood that I am currently running IS
about .25uv However, when I get the remote RX site(s) operating, Ill
be using Micor (AKA: SpectraTAC)
No. A typical UHF ham rig will have better sensitivity than most
repeaters with a preamp. A commercial mobile (without preamp)
will have
sensitivity slightly worse than the repeater with the preamp. 99% of
hams will be using a ham rig, not a commercial one.
OK, tell you what. It's
At 2/10/2006 21:54, you wrote:
At 03:48 AM 2/10/06, you wrote:
Maybe Jeff or someone could explain the math here. I find it difficult
to believe one needs to run 200 watts for reciprocal coverage to a
typical mobile. And that's ignoring where I live, you'll never get
frequency coordination
And that's my whole point.
Chuck
WB2EDV
Jeff DePolo WN3A wrote:
I'd be interested in someone actually trying this with a UHF
system that
is running 200+ watts. Drop it to 100 watts without telling anyone.
Leave it there for a week or two and see if anyone notices.
Chances are
In a message dated 2/11/2006 3:10:54 PM Eastern Standard Time,
[EMAIL PROTECTED] writes:
http://www.ve3tjd.com/pictures/tech%20stuff/
What a perfect heatsink for that variable power supply load that was
bouncing around on R-B about a year or two ago. You could vary the Amp Load on
your
Sure they would. There was a long time ham (now SK) who would not run
anything less than 100 watts from his mobile. Didn't matter what band --
had to be at least 100 watts or he wasn't happy.
I've seen the same thing in public safety service. For years you
couldn't get the local fire
Hi guys does anyone have that circuit diagram I need to build one to test
12 to 60 volt supply.
Thanks in advance.
Brett
- Original Message -
From:
[EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Sent: Sunday, February 12, 2006 10:01
AM
Subject: Re:
Here in OZ we only run 25 watts for mobile and 50 for bases / repeaters.
Cheers
Brett
- Original Message -
From: Chuck Kelsey [EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Sent: Sunday, February 12, 2006 10:02 AM
Subject: Re: [Repeater-Builder] UHF Power
Sure they would.
Re variable power supply load. Info should be in archives
section. I do have a hand drawn schematic somewhere in one of
mypaper piles. Will take a look. Maybe someone can direct Brett to a
better source for the schematic.
Gary K2UQ
YAHOO! GROUPS LINKS
Ron Wright, Skywarn Coodinator wrote:
Chris,
I think some of the responses about echolink to IRLP are correct.
IRLP is much more restrictive with their web police terminating
connections if the subject matter such as politics and religion are
discussed.
Maybe one or two owners might act
It is a Johanson model 5602 1-30pF. They are not easy to find and
expect to pay 10-15$ for one.
At times when I needed a replacement, I modified the disk to take 3
Johanson 5202 1-10pF trimmers in parallel which are much easier to find
cheap. They may even be higher Q than the single unit
Ken Arck wrote:
At 09:30 AM 2/10/2006 -0500, you wrote:
I thought one ran on Linux and one on Windows? Would you have to use
two computers?
---There are a couple of ways to do this on one computer. One way would be
to run WINE. Another is to run something called EchoIRLP:
OK, here are the results of my quick bench measurements for whatever it's
worth. All receivers were on the same frequency (448.800 MHz). Signal
source was a Fluke/Philips 6060A sig gen locked to a rubidium reference
oscillator, modulated by 1 kHz AF at +/- 3 kHz peak deviation. The output
of
And mine too. Just because the unwashed masses don't notice it doesn't make
it right, better, worse, or otherwise.
-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Chuck Kelsey
Sent: Saturday, February 11, 2006 8:46 PM
To:
Bob Dengler wrote:
Where was their web police last FD when we had a simplex IRLP node with a
broken RX connected to a reflector TXing all day on 223.50 the reflector
admin refused to disconnect it? Quite a mess that was.
Who did you contact Bob? I never saw an e-mail to any of the usual
It is yours.
Please send the mailing address to my email address; either the one in
the header or to [EMAIL PROTECTED]
The Icoms and the 103.5 reed are spoken for.
The 123.0 reed is still available.
David
KD4NUE
-Original Message-
From: Repeater-Builder@yahoogroups.com
Alright, I believe your numbers. A repeater receiver with a high-end
preamp vs. a ham grade mobile receiver averages just under 6 dB better.
I still contend that in a mobile environment, under motion, that the
user will not detect the 6 dB difference. It will be barely
distinguishable most of
At 01:15 PM 2/11/06, mch [EMAIL PROTECTED] wrote:
But, any 3 dB TX ERP loss is accompanied by a 3 dB RX loss as well. As I
said before, any antenna gains or feedline losses cancel out when it
comes to TX vs RX ability.
Joe M.
I agree, if it's a single duplexed antenna and feedline.
But in this
I guess I'll modify the challenge. Drop the 200 watt transmitter by
6 dB
and see if it gets noticed. Bench tests are a good yardstick. Real
world
applications can be different.
Chuck
WB2EDV
We could all probably save a lot of money by using RG142 or RG214
going up the tower. Why does
I
can't speak to 220 Mhz but can provide info on the history of our club 2 meter
repeater at 1200 ft on a triangle TV station tower.
single
DB224 on one leg about 2-3' out. mounted straight out form the point of
the leg. Worked great 60-70 miles out where you could see the
antenna but
Brett, I have a copy of a commercial "Load Bank" which is nothing more
than
a bunch of large resistors in a case controlled by switches.
I'll dig it out and scan it for you
These people get $3,000.00 for this package ! I have the stuff to
build one
and have about $75.00 invested so
At 09:13 PM 2/11/06, Laryn K8TVZ wrote:
I guess I'll modify the challenge. Drop the 200 watt transmitter by 6 dB
and see if it gets noticed. Bench tests are a good yardstick. Real world
applications can be different.
Chuck
WB2EDV
We could all probably save a lot of money by using
Does anyone know ifaAndrew 7/8
inchconnector (type L5PNF) will fitReopen 7/8 inch heliax cable ?
Thanks in advance for your reply.
Jeff Corkren/W5PPB
Raymond, Mississippi
YAHOO! GROUPS LINKS
Visit your group "Repeater-Builder" on the web.
To unsubscribe
Years ago I saw a homebrew version of that:
Twenty tungsten auto headlights in a metal box, with a switch
for each bulb, and a couple of heater blowers. Bulbs were
50 cents at the auto junkyard, as were the headlight switches.
They were wired so that the parking light position (half-way
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