antenna feed, OTOH, will make any duplexer moot due to all the
desense it will generate, sooner or later.
Bob NO6B
.
Bob NO6B
a pass cavity after the Micor circulator instead of a 2nd
circulator.
--
Tim
:wq
A vi command? That old text editor will never go away!
Bob NO6B
:
http://www.micro-tools.com/store/P-22/Stabilant-22-5ml-Kit-Makes-30ml-Of-22a.aspx
The description of how Stabilant 22 works reads very similar to the Caig
Labs DeOxIt products. A performance comparison between the 2 products
would be interesting.
Bob NO6B
which makes them legal here.
Good to know that the harmonic spurious is the same on VHF UHF - thanks.
Since you have both, can you shed some light on the differences between the
KG-UVD1P KG-UVD2D?
Bob NO6B
harmonic).
Bob NO6B
double sheilded cable which uses dissimular metals in the 2
(or more) shields will eventually cause rf noise .
No argument here.
Bob NO6B
spectrum efficiency, but 7.5 kHz is simply going too far. Heck, some parts
of the country can't even make 15 kHz work, have gone to 20 kHz spacing
throughout the entire 2 meter band.
Bob NO6B
don't need to know how much output power your TX is
running, so long as your users can hear it.
Fun to play with? Yes. Can solve some IMD/overload
problems? Certainly. But not a tool for any seriously
engineered RF system.
Bob NO6B
Really depends a lot on whose money you're spending. I've
on my trips into the LA area.
Were you a member of his system? From what I remember it was a VERY
private system: more than just CTCSS, DCS or DTMF to access it.
Bob NO6B
ahead of that first amp, and with less
loss hence lower NF.
IMO the Simrex amplified preselector is a space-saving compromise, nothing
more.
Bob NO6B
there are just too many unknowns in this beast to recommend
it. Sure it works for many, but it's by chance, not by engineering.
Bob NO6B
tried using
them on the duplexer output of my 2 meter portapeater.
Bob NO6B
would spread
faster than the Black Plague and no one would buy them
Not saying it doesn't work, but I am saying as an RF engineer that it's
impossible with the data in hand to properly apply it's use in a repeater
system.
Bob NO6B
is obviously better. The honest
to thyself person should determine the NF difference, which
is probably not a huge amount.
Once again, I'm still waiting for the NF numbers.
IMO the Simrex amplified preselector is a space-saving
compromise, nothing more.
Bob NO6B
Sure, it's a compromise that works
varies with the
model, it's very difficult to predict the dynamic range characteristics of
the unit.
Fun to play with? Yes. Can solve some IMD/overload
problems? Certainly. But not a tool for any seriously engineered RF system.
Bob NO6B
requirements and their support is outstanding.
...but what is the noise figure?
I'm going to ask this every time someone says they perform very well.
Bob NO6B
overload
problem from a TX over 1 MHz away from his RX. Not the best solution
(higher loss, can't be retuned if he ever has to change freq.), but I guess
it works for him.
Bob NO6B
loss, can't be retuned if he ever has to change freq.), but I guess
it works for him.
Bob NO6B
If you picked the UHF Simrex unit with less gain, more selectivity than
the standard model, then the noise factor should be better?
I doubt it. But without any real NF numbers, it's all guesswork.
I
is suitable for a particular application. Selectivity isn't
everything either.
Bob NO6B
At 7/27/2010 10:29 AM, you wrote:

Get a Mac. Much more efficient and crash free..
At the last coordinators' meeting I attended there was one laptop crash...
Yup, it was a Mac ;)
Bob NO6B
is that the
difference in phase noise between the 2 exciters would greatly diminish due
to the Q of the tuned stages in the multiplied exciter kicking in.
Bob NO6B
.
Bob NO6B
. The TX RX used tubes, required weekly tuning precise
aiming of the Yagi's null into the omni to keep the desense away. But it
worked.
If your target stations on either packet frequency are all in one
direction, a directional antenna may lessen your filtering needs.
Bob NO6B
-8 years before we see a USB interface on all
controllers?
Bob NO6B
only has 7 macros it's not
something you'd do very often. I haven't sent a 4th column digit to my
RLC-1 in over 10 years.
Bob NO6B
be the best choice
because IIRC it tries to mimic the ACC programming paradigm.
Bob NO6B
- the RLC-1 can be reprogrammed to use only 12 digits. I have one
in my system control it with a 12-button DTMF mic.
Bob NO6B
At 7/17/2010 14:04, you wrote:
I have no interest here...but why just say it can be reprogrammed
without explaining how. Thought the hobby was about
communicationsometimes I wonder!
What explanation?
Bob NO6B
D
On 17/07/2010 20:38:14, n...@no6b.com wrote:
At 7/16/2010 23:41, you wrote
Rick
I highly recommend LinkComm SCom. SCom has the best new product in the
7330 is cheaper, but LinkComm has several multiport controllers to choose
from. Both are far more versatile than other controllers.
Bob NO6B
NO6B
but nonetheless a solution:
http://www.piexx.com/index.php?main_page=product_infocPath=6products_id=31
Bob NO6B
to attempt. At 443 pages of disassembled source
code I'd say you really have to want to do something like this.
And I'm doing it for fun...
Was the original code done in an assembler (my guess, given the
vintage)? Have you asked Link Comm if by chance they have any source code?
Bob NO6B
measured show around 200 mW out. I once put a UHF
exciter tuned to 450 MHz on an HP437 power meter got 183 mW. This seems
to be more than enough to drive their RFPAs.
Bob NO6B
. Also never heard of any tin whisker problems
with those RXs, maybe because there's no tin in the helical housing?
Bob NO6B
on the COS active low on the CTCSS. That way any
failure that occurs equally to both lines will not key the TX.
Bob NO6B
the struck antenna on RX. Been working fine since.
Bob NO6B
into the phase modulator. Apparently it has a
very high impedance, as any load on it eliminates the problem. You might
loading the PL input on the Micor see if it has the same effect.
Is this a VHF or UHF radio, is it currently on the air? (I can probably
hear it from here)
Bob NO6B
in the state of California.
I thought they were perfectly safe because there's no prop. 65 warning
label on the radio ;)
Bob NO6B
years ago. Worked very well
though the actual gain is a couple of dB off from a GP9, as you'd expect
since it's about 5 ft. shorter than a GP9.
Bob NO6B
power without overloading the
spectrum analyzer.
Bob NO6B
porting code from the mid-range probably
wouldn't be any easier between the high-end PICs the Atmel.
Bob NO6B
At 5/16/2010 02:57 AM, you wrote:
Actually, Byonics is using the AT Mega (sp?). I specifically asked. At
least, that's what the TT4 is using.
They must have switched processors, as my TT3+ uses a PIC.
Bob NO6B
for ~$60.
I never saw any PIC-specific vendors at Dayton, though Byonics (APRS
trackers) is usually there as well as ICS (repeater controllers), their
products are PIC-based.
Bob NO6B
.
Bob NO6B
Miamisburg system. Has IRLP (node 4235) I've been told it now makes it
down to Cincinnati.
Bob NO6B
be done with PICs. I see Don's using
the analog input of a fairly low-end PIC, but I'd think you could use a
digital input if the output of the LPF was limited via a very high gain
amp. stage, a la ComSpec. Did he implement an IIR filter in the 12F675?
Bob NO6B
as narrow as
you want by selection of the loop filter capacitor value. The problem is
the decode time @ 1% BW, which can be as long as 2 seconds @ 100 Hz
according to the datasheet.
Bob NO6B
with temperature.
Bob NO6B
. It is audible over a fairly large (10 - 12 miles
that I've checked so far) area.
No idea what it is, but listen closely around the 9-10 second mark. Almost
sounds like a faint noisy echo, or perhaps a distant responding station,
which would be a form of ALE.
Bob NO6B
At 4/24/2010 20:20, you wrote:
Jim,
Try this guy, Kurt Gruber. kurtgru...@yahoo.com
That should be kurtgra...@yahoo.com.
Bob NO6B
repeaters try http://rptrlist.w6jpl.ampr.org.
Bob NO6B
want.
Bob NO6B
about. 1 is not enough @ 2
meters to make a significant change. Try changing the length by about a
foot for 2 meters, or 4 @ 440.
Bob NO6B
will
probably be lower.
Bob NO6B
AC fans because they generate less noise. I do have some 12 V CPU
fans on the backs of a couple of MVPs in service, but have had problems
with low levels of fan noise on some of them. If you have a choice, AC
fans are easier to work with IMO.
Bob NO6B
. Had
to pull the exciter out of the MVP put it in an RF-tight box, but there
were no problems after that.
Bob NO6B
are becoming quite the weak link in this radio series. Thank
goodness for DeOxIt.
Bob NO6B
if it didn't.
And dos the Length of the Coax going to the Micor /Mobile have to be
cut at a Certain Length
No.
Bob NO6B
features of the D-Star
protocol are required by your EmComm entity.
Bob NO6B
filter, definitely. The Cross Country Wireless filter, though
interesting, is way too wide for this application as it doesn't even have
good rejection @ 150-160 MHz.
Bob NO6B
of that.
Bob NO6B
decided to buy a D-STAR HT so he could listen in eventually
make contact. As soon as they heard another voice they were gone
haven't been back.
Bob NO6B
At 3/31/2010 05:20, you wrote:
I'll take copper any day. As Jeff said, one site visit to fix a bad
aluminum cable connector on the top of the tower and you've lost all
that you saved plus more.
Jope
Aluminum hardline was once banned at one mountaintop site I rent from.
Bob NO6B
of STE. Dropping tone is a crappy way
of doing STE, since you have to hold the TX on for at least a 3/4 of a
second to make sure all the decoders have stopped decoding.
Bob NO6B
scanner using LED bar
graph displays instead of meters. Batesburg, Va. Wasn't it? Never heard
anything about them after that.
Sounds like my FM-110. AIE is still around but no longer in the service
monitor business.
Bob NO6B
have both MVP (Versatone, which respond to G.E. reverse burst) Mastr
Pro RXs (don't respond to reverse burst) uplink RXs in my system, so I
added a delay to my Mastr II uplink TX in order to get reverse burst
followed by about half a second of unmodulated carrier before TX drop.
Bob NO6B
of the country to be quite abiding of speed limits. And I've
also found the local law enforcement to be quite efficient in enforcing
said limits.
Bob NO6B
+Users+Beware/article17869.htm
If the performance degradation ends up being significant, don't be
surprised to see 3rd party native support for the 4k block size appear,
similar to the non-Microsoft USB drivers for NT 4.0.
Bob NO6B
the club's user base for HTs to work
there. Funny how after the repeater was sold off to yet another trustee,
it suddenly began to receive well again. That's when I found out what was
done that made it so deaf in the interim.
Bob NO6B
of an open, on
the inductive side.
Bob NO6B
choice, but if he's already got the cans, a pair of 1/4
wavelength cables will be much cheaper.
I'd stay away from using a broadband isolated power divider (splitter), as
you'll lose 3 dB in the split. The frequency-splitting options lose
virtually no signal.
Bob NO6B
NO6B
At 3/5/2010 15:32, you wrote:
re: Someone still loves a Motrac - Low Band Even...
Made me smile to think someone bid on the radio.
It's already xtal'd up working on a popular ham freq., so that makes it
worth something.
Bob NO6B
!
(hams)
I can see it now - Live from Dayton... the Hamvention Robot.
For the price of a Recon Scout, I could've bought 2 10 kW AM broadcast
transmitters at last year's Dayton. Or was it a 3 kW transmitter for $10k?
Bob NO6B
.
Bob NO6B
are spec'd to withstand 20:1 VSWR. That's
a lot of reflected power, probably more than what you'd ever see if your
repeater antenna opened or shorted due to the feedline duplexer losses.
Bob NO6B
is likely either in the RBI-1, radio cable, or radio.
Bob NO6B
that will solve all of his IMD problems. Will let
you know...
Bob NO6B
was partially cured here by spraying some conductive
paint into all the tower joints. Each time it was done the interference
would disappear for a few months, then return.
Bob NO6B
netting the xtal).
2. Set LO freq. per above.
3. Tune front-end.
4. Move sig. gen. freq. +/- to see if RX is centered.
5. If RX is not centered, tune IF for best SINAD.
6. Repeat step 4. If RX is still not centered, move LO freq. to center IF.
Bob NO6B
A while back I posted a WTB for the above. A few people responded but
unfortunately the e-mail chain on the one good prospect seems to have
gotten lost.
So once again I'm looking for a used 220 MHz pass cavity (not pass-notch,
not window filter a la DCI). Thanks.
Bob NO6B
I'm looking for a used 5 to 11 element 440 Yagi. Need to have it by
2/18. Haven't found anything reasonable on eBay, eHam or at the local swap
meets. Please reply direct to no6b at no6b dot com.
Thanks.
Bob NO6B
cause
it to transmit more than half the time I could turn it down to low power.
Bob NO6B
to the antenna port.
Most mobile duplexers are rated for 50 watts max. TX power. That rating is
quite accurate.
Bob NO6B
that would make user programming of the
callsign, interval, tone freq., etc. easy.
Bob NO6B
problem in an antenna system that couldn't be accessed at the time.
Bob NO6B
' horizontally with a single pass
cavity on the TX. The transceiver was all tube the RX antenna was a beam
nulled into the TX antenna. I had to retune the TX about once every 2
weeks keep the sharp null of the Yagi on the TX antenna, but when this
was done there was no desense.
Bob NO6B
was generated whenever the
antenna system was driven with RF.
My advise is to try a different antenna/feedline at the site see if your
desense goes away.
Bob NO6B
At 1/10/2010 06:34, you wrote:
Hi,
Does any one in the groups have on of these in their junk box that they
don't need?
I'm missing a couple of those myself for the pass version of those
cavities. I would be interested if there's a standard/plentiful source.
Bob NO6B
is now my
backup TX antenna.
Bob NO6B
) is 94830A550: $7.47 each.
Bob NO6B
pressure to provide an adequate lock of the tuning rod; I think not.
Sal's idea of using small hose clamps is starting to look good ;)
Bob NO6B
care
about the close-in coverage. At 15 miles away the main lobe hits the ground.
Bob NO6B
to maximize the coverage the antenna will only be 20
feet up. Clearly this calls for a higher gain antenna.
I recommend the Comet GP9. It has 11 dBi gain on 440 MHz, on the horizon,
also works well on 2 meters in the event you want to add a remote base.
Bob NO6B
supported pulse service
not owning a rotary phone (I'm not an antique collector), I picked up my
touchtone phone hand-pulsed the hook to dial my wife's cell phone. It
worked.
Bob NO6B
be used.
RG214 is the best choice for hardline-to-antenna jumpers. I also use is
for the duplexer-to-radio cables unless I need more flexibility, in which
case I use RG223.
Bob NO6B
to be dissemilar metals. I once confirmed a 100%
copper braided RG-213 jumper as a PIM source. I only use silver-plated
braided coax beyond the duplexer from now on.
Bob NO6B
connected to. I have one in use for a TX-only
link. Someday I'll take it down replace that harness with RG142 or RG214.
Bob NO6B
at full power I never have any power
issues with it. The link is set to around 3-4 watts, when it gets well
below freezing it takes a couple of seconds for the TX to make enough power
to establish the link.
Bob NO6B
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