exciter RX LO chain
aren't sitting side-by-side. I've tried bypassing the 10 V supply adding
shielding to the exciter area to try to prevent coupling between the RX LO
chain exciter, but have had no success.
Bob NO6B
MVP
with speaker audio going straight into the mic input using only an 8 ohm
load resistor, coupling capacitor resistive divider to get the level
right. It did sound quite good, but I suspect this is more the exception
than the norm.
Bob NO6B
is only rated for 150 mA output sink, it
could easily switch 400 mA. You might want to take a closer look at your
controller to see if any sort of buffer circuit is actually necessary.
Bob NO6B
or assembled and tested.
Good controllers, IMO:
-LinkComm
-S-Com
-MP100 by WN3L KA9FUR (no longer in production)
Everything else is 2nd rate in comparison.
Bob NO6B
transistor (i.e. 2NA)
output |
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-
Leave it to YahooGroups to mangle simple plain text!
I'll send it directly to you, Kevin.
Bob NO6B
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A high logic output level will pull the collector of the NPN low, turning
on your fans.
For this to work, your logic output needs to be able to sink 5 mA.
Bob NO6B
-emphasized (I
think it is in the Kendecom RX), then you'll need to activate de-emphasis
on that controller port (usually a jumper or install a capacitor).
Bob NO6B
with a multiport
controller. I've received reports of problems with the front end helical
filter response after modification (excessive passband ripple), so I've
backed off until I get some free time to investigate this issue.
Bob NO6B
output capacitor, so I added more solder
wick across that break up the foot of the cap. That was probably 10
years ago since then that PA has carried many a shuttle mission ISS
audio to boot, putting out the same power now as when the last repair was made.
Bob NO6B
made 200 mW. One I did measure with an HP437 power meter put out 184 mW @
450 MHz. But 100 mW is a bit low.
Bob NO6B
area; that fix stuck.
Bob NO6B
(at least on all
controllers I know of).
Bob NO6B
At 11/25/2007 19:50, you wrote:
The Linker IIa is a 2 port controller with a seperate control receiver input.
The control receiver input has priority over RX1 and RX2, RX1 has priority
over
RX2.Â
Can it mix RX audio from ports 1 2?
Bob NO6B
port has a signal, the other port is
inhibited.
How much distortion do you get using those 4011 NAND gates as audio amps?
Bob NO6B
that they couldn't hear the courtesy tone
anymore. They still wanted to use decode so as not to hear IMD yet still
hear the courtesy tone, so we had to set up the repeater so that encode is
always on when the node is not in use. To each his or her own, I guess.
Bob NO6B
At 11/23/2007 09:20, you wrote:
Would quad bilateral switches like a CMOS 4066 better for switching the
audio lines?
Dave WB2FTX
Well, if you're asking me how I'd do it, see the attached. It's a bit
fancier than Jim's circuit, but it's untested because I determined that the
resulting board
channel that was
topic-specific. For example 9255 is used specifically for balloon flights
discussions.
I personally find Echolink totally useless while on travel. Too hard to
find nodes because the locations aren't properly cataloged.
Bob NO6B
At 11/18/2007 06:50, you wrote:
Imagine your 2M or 70CM base station were on a tall, tall, tower and you
can key and operate any one of 140 different repeaters world wide, no
noise, static, etc.
Thats DSTAR today.
That's also IRLP Echolink today, albeit with much greater coverage.
Bob NO6B
At 11/9/2007 13:12, you wrote:
I know of very few who do this.
Joe M.
I don't know of anyone that does this. Yet it is in the rules.
I think the legal out here is that automatic control relieves the need
for remote control, with only the latter requiring the heartbeat timer.
Bob NO6B
- or another list.
But, you brought up the original question - DOES the automatic control
relieve the need for any other control?
Yes, so long as compliance with FCC rules is achieved.
Bob NO6B
in a capacitive sense. This page
provides a pretty good description of what actually goes on inside an EPROM:
http://www.tech-faq.com/eprom.shtml
Bob NO6B
that mean that the link must be active at all times?
Yes, at least once every 3 minutes. If input from the control station is
not present for more than 3 minutes, the remotely controlled station is
supposed to shut down. This is known as a heartbeat timer.
Bob NO6B
At 11/9/2007 07:01, you wrote:
Laryn,
My only reason for thinking 2.4 G would not be legal for control it did
not fall within the Auxiliary frequencies allowed for control or Telecommand.
The entire 2.4 GHz amateur band is available for auxiliary stations.
Bob NO6B
At 11/7/2007 11:28, you wrote:
But where does it require a control link (AUX station) to control the
repeater? (or landline ot local)
97.213(a). Remote control may only be performed by telecommand, , only
auxiliary stations may provide an over-the air control link.
Bob NO6B
frequently run in-band full duplex. Just sort of an old
habit :-)
I assume your repeater doesn't have ADMs.
Bob NO6B
what it is, it performs exceptionally
well. I have one literally sitting in the middle of downtown LA @ 1000 ft.
AMSL with nothing but a notch duplexer between the RX the antenna, it
hears quite well with no IMD.
Bob NO6B
rule applies. So if a
repeater is being operated under remote control, this rule applies.
Bob NO6B
At 11/2/2007 22:30, you wrote:
Only if you're using a rig with a skewed S-meter (and today many are
made that way). There are standards for proper S-meter calibration.
No S-meter involved. A 3 dB increase in signal can make the difference
between unreadable readable.
Bob NO6B
don't hold up well to UV,
winds, rain, ice, etc.
I would always use some form of hardline, superflex ideally.
I've never had a problem with RG-214.
Bob NO6B
3 dB is definitely noticeable on my RXs.
Bob NO6B
At 11/2/2007 13:33, you wrote:
Is it worth one S-unit to you? That is the real question.
Joe M.
Tony L. wrote:
I've asked this question before, but will ask it again just to see if
there are any new twists that I'm unaware of:
Our
community.
Bob NO6B
/Active_component
Bob NO6B
not saying that circulators don't need harmonic filtering, just that
there's no guarantee that one will in fact act in a nonlinear manner,
particularly if driven below saturation. You have to measure it to be
sure, otherwise be safe use a LPF or bandpass cavity.
Bob NO6B
NO6B
companies know that, stick the
local must carry sellavision channels that nobody watches there.
;)
Bob NO6B
. A diode is passive nonlinear, while a class A amplifier is active
(hopefully) linear.
Bob NO6B
can cut down
on the electric bill, but not for mountaintop use because of the
reliability noise issues. As long as I'm not billed for the electricity
my systems use, I'll stick with linears.
Bob NO6B
that the interfering signal on the input had a beat to it ;)
Bob NO6B
to prevent the mix from being generated
on all the 440 inputs, but eventually the paging TX went away, the site's
been very clean ever since.
Bob NO6B
works even
better. :-)
Have any FM broadcast TXs up there? I've noticed a correlation around here
between their presence the deafness of all 2 meter repeaters at the same
site.
Bob NO6B
0.2 µV I could still access it when I wasn't
getting enough return signal to hear the stations talking to
me. Apparently the site noise receiver noise temperature is very low.
Bob NO6B
Bob,
I have laid hands on many systems in the area you mentioned. Which one are
you referring to? I may be able
.
Bob NO6B
they may have a remote RX for their repeater installed in the area. Not
quite as portable as just the radio duplexer though.
Bob NO6B
Cut down your MP100 ;-)
-Steve
I've been seeing a lot of this lately: forwarded posts with no added
text. Is there a problem at Yahoogroups or are people having problems with
their mailers?
Bob NO6B
to face reality in that many radios
bias the mic input.
BTW, there is a solution to this problem that uses only polarized caps, but
I've got to run down. Will follow up if anyone's interested.
Bob NO6B
transmitter audio outputs and each of the three CTCSS encoders.
Thanks for the info, Bob. How big are those SMT caps? I'm wondering if
NHRC can retrofit their 1 µF polarized with those, or perhaps even just 1
µF non-polarized.
Bob NO6B
suggestions, if B-D
Enterprises ever returns its 1P controller to production, please let us
know. Thanks.
Bob NO6B
the open source of the hardware.
If there is any intrest I will finish the PCB, which will measure 1.9
X 2.5 and about 0.5 tall and doesn't use any surface mount
components.
I appreciate the effort, but for this task I need a ready-to-go solution.
Bob NO6B
it, simply unplug P13. This also removes the 620 ohm load, allowing
driving the MIC HI input with somewhat higher output Z sources.
Bob NO6B
I'm once again looking for a small controller that fits within the
multi-freq. area of a G.E. MVP radio. The available area is 5 x 2 x
1.25. The NHRC-micro is not a consideration, as it is the defective
controller that is being replaced. Thanks.
Bob NO6B
to the user to provide proper input
filtering.
Bob NO6B
, repeaters can operate there so long as they
do not cause interference to simplex operation on those frequencies.
Bob NO6B
it isn't, as Echolink IRLP have a legitimate home here.
Bob NO6B
., normally full quieting signals are
completely captured by the noise. I suspect it's the electronic scroll
sign on the back of the bus.
Fortunately I haven't seen this on 440 MHz, but with faster CPUs finding
their way into everything it may only be a matter of time.
Bob NO6B
might consider adding a preamp an additional
pass cavity in front of the analyzer to maximize sensitivity if at first
you don't find anything.
Bob NO6B
not be necessary to
change the rules.
In essence, it's an admission of guilt by wanting to change rules they
claim they are not in violation of. If you're not in violation, why do
you want the change?
Who wants to change the rules?
Bob NO6B
become as popular as it has because
of the potential to divide what was once a fully compatible, interoperable
ham community. But as a frequency coordinator, it's not our place to
dictate to our constituents what modes they may or may not use.
Bob NO6B
accepted as such.
Bob NO6B
, but if they operate within a
network
of cooperating amateur stations, they can be classified as auxiliary
stations. The definition as written is rather loose, but that is a debate
for some other reflector.
Bob NO6B
You're right-the definition is pretty loose. Some of it is dependant on
the intent
-50s lying around for the next one of those we run into.
W.r.t. RX specs, are you saying your spec. for -85 dB total BW is 60 kHz?
BTW, our specs are at http://www.tasma.org/devdata.htm
Bob NO6B
for the 2 together would be wider.
Correct. The only way to take advantage of D-Star's narrower bandwidth is
to pack D-Star systems adjacent to each other.
Bob NO6B
,
145.595, 145.605 145.615 outputs (inputs all -600 kHz). With the 10 kHz
spacing, currently only DStar systems are compatible so they're essentially
DStar pairs.
I expect all 4 pairs to be assigned to 1 or more DStar systems at our next
coordination meeting.
Bob NO6B
Bob,
Does this mean
know there were some
changes in Dec 2007 about 2 meters although I did not think the repeater
and aux bands changed.
They did.
Bob NO6B
in the above context carries as
much weight as the frequency coordination itself
Bob NO6B
some problems getting
coordinated.
Bob NO6B
the mess you describe above. I know we (TASMA)
wouldn't coordinate such a system.
Bob NO6B
At 8/31/2007 10:02, you wrote:
Along with that question, is the banned aluminum coax the old unjacketed
stuff like the CATV folks use, or is that any aluminum coax? I'm thinking
I think it was any aluminum-shielded hardline.
Bob NO6B
spacing, currently only DStar systems are compatible so they're essentially
DStar pairs.
I expect all 4 pairs to be assigned to 1 or more DStar systems at our next
coordination meeting.
Bob NO6B
At 8/31/2007 14:38, you wrote:
If aluminum were banned from most sites there would not be many systems on
the air. It s only when
Not aluminum altogether but just aluminum-shielded hardline.
Bob NO6B
.
They are for auxiliary stations. Auxiliary stations may use 144.50-145.80 MHz.
Bob NO6B
that a repeater coordinator's technical standards
would be a bit above the mess you describe above. I know we (TASMA)
wouldn't coordinate such a system.
Bob NO6B
You guys have control of the quality level of the equipment used when
issuing coordinations?
We have control of the technical operating
that which is used for analog
repeaters. In fact, I'd expect D-Star to be somewhat more tolerant of
on-channel interference because of the error correction.
Bob NO6B
. After that you can find the others by kerchunking (with
ID of
course!) all the other pairs with that tone.
Bob NO6B
It seems to me that if you have all the repeaters in an area
running the
same CTCSS tone, and start fighting a mixing problem... everything is
going to be back
amount of change.
I never found the 555 to be very stable; the XR2206 always did better.
Bob NO6B
at the end of
the feeding coax, thus eliminating the mismatch.
My guess is that the higher power reading on the wattmeter is due to the
weird impedances it's seeing on both its input output.
Bob NO6B
them for decoding column 0 tones (147* column tone shifted
down). That worked until someone recorded us on the input played the
tones back :(
No, my favorite was the SSI-202. Not too expensive trouble-free decoding.
Bob NO6B
with that tone.
Bob NO6B
It seems to me that if you have all the repeaters in an area running the
same CTCSS tone, and start fighting a mixing problem... everything is
going to be back to keying everything else in short order.
This gets us back to the CTCSS-bandaid issue. If your ham TXs
Rs Cs did I discover when trying to build a 1000 Hz sine generator that
the chip temperature affects the operating frequency.
Bob NO6B
NO6B
greatly reduce the
aging rate (why I only heat to 120 F: the lowest temperature I can achieve
stabilization, as even that temp. sometimes causes noticeable aging
acceleration).
Bob NO6B
wasn't so
unfavorable.
I don't bother with compensation; I temperature stabilize. For me, it's
the right thing.
Bob NO6B
P.S.: Anyone know of a source for retrofit DDS modules for G.E. MVPs? The
DDS chips are getting cheap enough now that a finished product for older
LMR equipment should
of
business. But that's just IMHO; YMMV.
Bob NO6B
Angle Linear here.
Bob NO6B
that the insulation has any
significant effect due to the small amount short length of the connector,
hence not enough length to cause any impedance transformation.
Bob NO6B
-silver plated
braids of some RG214, for example.
Ditto here; have found the exact same results via real-world experience.
Bob NO6B
(e): An auxiliary station may transmit one-way communications.
Amateur paging, at least as how I use it, is a one way transmission from
the auxiliary station to the pagee, is not broadcasting, a
one-to-many transmission.
Bob NO6B
talking apples oranges here. 600 kHz is for
same-system input to output spacing.
Bob NO6B
of the
3rd party DStar groups put together. I can say that it's not
vaporware: it was operating showing various parameters of the received
DStar signal.
Bob NO6B
the compression feel it adds intelligibility. Certainly
much better sounding than the Mototrbo demo on the page recently posted here.
Bob NO6B
) bandwidth is ~20 kHz,
the 50 dB bandwidth of DStar appears to be about 10 kHz. Here in SoCal
we're proposing 10 kHz channel spacing for DStar, digital P25 any other
very narrow band digital voice, or VNBDV, systems.
Bob NO6B
At 5/24/2007 03:37, you wrote:
Whoops. Should have said no movement and I should have changed the subject
line.
Chuck
I've had problems with RG-213 jumpers lying on the floor inside the shack
that caused desense. Movement of the cable is not necessary to cause desense.
Bob NO6B
, to
defeat that feature you have to power it on while holding down the blue
button for 2 seconds. A total PITA IMO.
Bob NO6B
...in the photos section.
Bob NO6B
-proof front end than the Mastr II. I used to have one at
a major comm. site; RX was connected directly to the RX antenna on the
tower - no filtering. Very good sensitivity no IMD.
Bob NO6B
it, as devising non-applicable
circuits or procedures won't make it go away.
Bob NO6B
link show up at one site that was pretty much in the middle
of the input band, only 140 kHz away from an input I maintain. However, it
never bothered that input in any way so we let it slide.
Bob NO6B
like himself.
Correct. The 3-minute rule does NOT require a time-out timer, but rather a
control link watchdog timer that AFAIK nobody uses.
Bob NO6B
rule in the book. To answer the subject
line, yes it is a myth.
Bob NO6B
couple the audio gating TX keying, IOW you can't have a situation
where the repeater will drop even though audio from the weak station is
still passing, or the repeater hangs on a weak signal that isn't quite
breaking the squelch. I've heard both conditions on a stock Micor repeater.
Bob NO6B
.
Bob NO6B
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