Hi Josh,
You can mod your Micor, but you'll keep running into similar problems when you
interface your controller with other repeaters. COR outputs can be driven by
Darlington transistors, LED drivers, squelch ICs, etc., and not all will go as
low as you want.
Here's how we've designed our
Hi Jeff,
Here's how we've designed our controllers' COR, CTCSS, and
logic inputs for many years: Feed the COR signal to the top
of a voltage divider. The upper resistor is 10K and the lower
is 4.7K. Feed the junction of the divider to the base of an
NPN such as a 2N3904, 2N, etc.
Hi Scott,
Many controllers have pullup resistors on their COR inputs so that they can be
driven from open collector or relay contact COR outputs. With that arrangement,
if the controller is configured for active high and the COR line is
disconnected, the controller will think the receiver is
Hi Jeff,
what are you using? are Arcom? or Scom?
I exchanged messages with Jim. He's building his own control system.
If your using a arcom, take the jumper out of the delay board headers that
jump the audio for each port, bring the audio out line (JP10-2,JP11-
2,JP12-2) from each header
Hi Jeff,
In general I don't like raising the ground on 7xxx series fixed regulators
by adding diodes to what would normally be the ground lead.
You're right, the diode trick is not recommended. National recommends putting a
voltage divider across the output of the regulator and connecting the
Hi George,
Anybody know the command to set the time date on an S-COM 5K with older
firmware? Possibly v1.5 (I don't have it here in front of me...) The only
owner's manual on the S-COM site is for v2.0.
The command was changed because the software real time clock in V1.x became a
Hi Guys,
W0INK studied and reported on that topic some time ago:
http://www.scomcontrollers.com/downloads/ctcsssrejecthpfilters.pdf
73,
Bob
Bob Schmid, WA9FBO, Member
S-COM, LLC
PO Box 1546
LaPorte, CO 80535-1546
970-416-6505 phone
970-419-3222 fax
www.scomcontrollers.com
-Original
I was looking for a picture of Mike, not a picture
of a car that Mike took.
Mike's a car thief?!?
73,
Bob, WA9FBO
Hi Dave,
The systems we've worked on in aviation follow a standard EIA tone format which
is probably similar to yours. On depressing the PTT bar on the handset, the
encoder transmits a guard tone burst of 2175 Hz at a high level followed by one
of several possible?function tone bursts known as
Hi Bob,
This may or may not apply, but chip capacitors,?also known as?MLC
(multi-layer ceramic) capacitors,?can fail from stress cracking?if?unevenly
heated during the soldering process.?For this reason MLC?manufacturers advise
against?hand soldering as the?fractures can be hard to see -- and
Don,
And?when are the?existing repeater owners are going to *SEE* new additions in
programming to the?7330 SCOM controller?
There has been a series?of?software?upgrades for the 7330 since its
introduction,?and the latest will be coming out as soon as one last item is
fixed.
Be aware that?we
Hi Kim,
If the repeater has been inactive for a while, when it first transmits it
sends its I.D.? Since I don't want to be 'washed out' by the I.D., I kerchunk
the repeater.? Once the I.D. has finished, or the I.D. has not been sent, I
will then put out my call to see if anybody's on the air.
Hi Don,
and where in the Heck did this Word KERCHUNK Originate from We all know what
it means
Early tube-type?repeaters?used large relays?to key the transmitter. When
someone keyed and unkeyed the repeater the result really was a loud?kerchunk
at the site. It led to what we now call courtesy
Hi Mark,
Bypass the gate of the crowbar SCR with .001uF to ground (and put it?very close
to the gate).?As mentioned previously,?RF is getting into your crowbar
circuit?-- this is a fairly well-known problem.
73,
Bob, WA9FBO
-Original Message-
From: n9wys [EMAIL PROTECTED]
To:
Hi Derek,
We replaced the FR-4000 with a Kenwood 850 only because after 3 people
trying for an entire saturday afternoon, we couldn't get the FR-4000
to play with an SCOM 7K controller.
Can you supply some details of the problem you had? We've always glad to
help when asked.
73,
Bob
Hi Ian,
Does anyone have any info on the unit in question that generated those
tones? I'd love to find one - just for memorabilia.
That tone format has been around for a long time in mobile radio (Motorola
Quik-Call I) and is still being used in aviation (ICAO SELCAL) to page
aircraft on
Hi Guys,
Thank you to all who responded to my inquiry, through the list and
privately, for your insight. The tech committee now has more info on which to
base its
decision.
73,
Bob, WA9FBO
**New MapQuest Local shows what's happening at your destination.
Dining, Movies,
Hi Joe,
I'm still trying to comprehend why you would need replacements just
because a site is more quiet. If they work at the crowded site, they
should work fine at the quiet one.
That's just it --?they don't work all that well at?this mountaintop site with
literally hundreds of RF sources.
Hi All,
My club has some 3-year-old VHF and UHF Vertex repeaters at a high-RF site.
A possible deal would move them to a much quieter site, and if that happens
we'll need replacements.
Members of this list have consistently shown a preference for Kenwoods, and
it appears both brands are
Hi All,
Please note some items that should be considered when making a commercial
version 2175 notch filter.
Not all remotes and consoles generate a precise 2175 Hz tone. Older units
use LC oscillators that can drift, while newer ones are crystal controlled and
are more accurate.
A
Hi Joe,
The best PL filter I ever saw was one I built out of a digital SCF design a
couple of years ago.
I realize that the paper is referencing commonly available products, but I
wish someone
would make this thing up for sale.
Here is a link to the data sheet:
Hi All,
There was a discussion on Repeater-Builder a while ago about the advantages
and disadvantages of various commercial CTCSS highpass filters.
S-COM's analog guru, Virgil, W0INK, did a careful analysis of five common
highpass filter designs: Comm Spec TS-32, Comm Spec TS-64, Micor
Hi Bob,
My recommendation for a 3-port controller is the SCom 7330. It's a bit
more expensive that the RC-210 but IMO is of higher quality. All ports
have dedicated hardware (tone CTCSS generators, voice, etc.).
Apples-to-apples:
An RC-210 ($325) with an RC210R cabinet ($75) and an RAD
Mike,
NEITHER the ARCCOM or the SCOM 7330 will work if you intend to do anything
more than fairly basic things.. a repeater, a remote base on a fixed freq,
etc, etc.
Fairly basic things?
If you think this stuff is easy, you haven't investigated what it takes to
make one controller
Hi Don,
If any of you remember the date when the 7330 was first announced in
comparison to today's date, you'll recall that it's been quite a few years.
No, the 7330 is a recent design. But besides the 7250 (the forerunner of the
7330), there were two other successors to the 7K that I
How could it be more sensitive with CTCSS? I'm not sure I
understand.
de N5ZTW
A CTCSS decoder looks for a precise tone frequency in a narrow band, so it's
fairly sensitive.?A squelch circuit?looks?for noise (no signal present) and
loss of?noise (signal present)?in a much broader band?above
Hi Mike,
Thanks for the cursory review Skip. I actually sent via the website a list of
about 6 specific questions about the SCOM 7330 .? Have NOT HEARD A THING back
from them which is most encouraging.? Perhaps they are going to join the list
of manufacturers who are going to go out of
Hi Jim,
I have a commercial application to monitor the battery status and charge
current at a solar site and asked for information on controllers that would
allow me to monitor these parameters by requesting a voice readback.? I was
immediately answered by Ken Arch (sp?) and another RC-210
Hi Dave,
The 7330 is an S-COM product. The website is www.scomcontrollers.com.
73,
Bob, WA9FBO
-Original Message-
From: N0ATH [EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Sent: Wed, 6 Aug 2008 4:36 pm
Subject: Re: [Repeater-Builder]SCOM 7330 Question
I would like to
Hi Mike,
On a quick look at the available controllers around the SCOM 7330 looks
like a fairly new kid on the block. I wonder if anyone has had any experience
with this model or SCOM as a whole?
Since I'm a Member of S-COM, LLC, feel free to suspect that my comments
are slightly
Hi Rod,
The voice of the S-COM 7330 controller (and the Vyex Digital Audio Board in
the 7K controller) belongs to a ham by the name of Sean Caldwell
(_http://www.seancaldwell.com_ (http://www.seancaldwell.com) ). He gives price
breaks to
hams.
73,
Bob
Bob Schmid, WA9FBO, Member
Hi Bob,
Does anyone have a hex image of an S-Com 5K version 1.3 that they can send
to me ?
Version 1.3 was active only from September 1987 to January 1988.
Other than upgrading to V2.0, the best I can offer is a V1.5 EPROM in
exchange for the postage. The differences between V1.3 and
Hi All,
I'm very pleased to announce that after nine months of beta testing, the new
S-COM 7330 Triple Repeater Controller is in production and available for
sale!
A total of 66 units were tested by 54 repeater owners, and the results fed
back to the design team of five engineers (four
Hi Eric,
The world would be a better place if repeater controller manufacturers
included reverse burst capability..i
S -- don't tell anybody, but the 7330 supports both standard reverse
burst formats... :-)
73,
Bob, WA9FBO
**See AOL's top
Hi Joe,
The delay board we are going to be using is adjustable
for 64, 128, 256, 512 or 1024 milliseconds of delay. (NHRC-DAD board).
That delay board uses the MX609 Delta Modulation CODEC, a device with a S/N
ratio of 30-35 dB (at the highest sampling rate; varies with frequency)
Hi Jim,
Makes a pretty clean installation, although one
of the controller manufacturers on here recommended
against using computer serial cables as interconnects
for controllers
That'd be us. A PC cable consisting of two D-sub connectors and a long,
25-conductor cable enclosed within
Hi Mick,
I am running a Hamtronics receiver on our 53.090/52.090 repeater.
Should I use discriminator audio or squelched audio from the speaker.
Speaker audio is usually not a good idea. Not only does it have the highest
distortion of any point along the audio path, but if someone
Hi Gran,
On Superstition mountain in the Imperial Valley we have a S-COM 5K
that has taken repeated dumps after power line failures. The
controller is running off an Astron 35A supply. By dump I mean the
only problem is that the controller has to be re-programmed after the
AC power line
Hi Nate,
Pet peeve alert: Controllers seem to add features, but they're far
less useful on-site for control as they are for remote control.
I suppose it's a cost vs. necessity thing, since no one's at the site most
of the time. But we've learned about LEDs -- not only do they help
Hi Gran,
I am sure this 5K does not have the V2.0 upgrade. There is one other piece
of information of interest. In the last two outages other commercial
equipment also had programming problems. I have to wonder if the 5K is
susceptible
to low voltage. The dropping of a single phase
Hi Ben,
I'm looking at a TPE voter one of the list members has. Anyone on here
ever heard of it or know anything about it?
It's not made by this S-COM, anyway.
73,
Bob, WA9FBO
S-COM, LLC
More new features than ever.
Hi Eric,
I make no secret of my disdain for bells and whistles like clever courtesy
tones, autopatch, and voice announcements. I work primarily in commercial
and public-safety radio systems where such features have no place.
That's certainly an understandable take, but keep in mind
Hi Jim,
The cable I used was armored with a spiral copper
shield over 5 twisted pair lines. I did try grounding
the shield at one end, and at both ends with no
results. Putting caps across the twisted pair and to
ground also did not eliminate the problem, but did
reduce it. I used 600:600
Hi Joe,
TA51 transmitter. Here is the real problem. I can only get 2.5Khz
deviation of clean 1000Hz audio out of the transmitter. I can push it
to 3Khz, but it gets distorted.
That transmitter uses an RC phase modulator instead of an LC phase
modulator, which means the maximum phase
Hi Eric,
The Dallas Semiconductor Nonvolatile Timekeeping RAM found in many
popular
controllers, including the Link RLC-1 Plus, is Part Number DS1643-150.
We have a lot of experience with the DS1643 and its bigger brother, the
DS1644. The S-COM 5K uses the DS1643 (8K RAM), and the 6K
Hi Bob,
The new 7330 uses 10 uF ceramic SMT caps to couple each of the three
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
Hi Bob,
I know high-capacitance non-polarized caps are hard to come by in SMC form,
but controller manufacturers have got to face reality in that many radios
bias the mic input.
Done.
The new 7330 uses 10 uF ceramic SMT caps to couple each of the three
transmitter audio outputs and
Hi Guys,
I don't particularly care for MOVs because of their inherent wearout
mechanism. When the voltage across a MOV reaches the breakover point, the MOV
conducts and turns the excess energy into heat. Problem is, its breakover
voltage
then increases and it will allow more of the
Hi Larry,
Any suggestion on repeater controllers using radio link to irlp repeater
does not have audopatch...
The new S-COM 7330 will do it (_www.scomcontrollers.com_
(http://www.scomcontrollers.com) ).
73,
Bob
Bob Schmid, WA9FBO, Member
S-COM, LLC
PO Box 1546
LaPorte CO
Hi Joel,
The AP4800 is a 1994-era controller that used an Intel 8748 or 8749
microprocessor. Since the controller's operating system was stored in the
processor's
internal memory, you'll either have to find a programmed processor or get a
blank one and have it programmed by someone who
Hi Joel,
I thought that may be the other way out, but, know nothing about
programming proms nor have a programmer, nor anyone in my country to do such,
do you
know someone capable off such, Bob? any help will be appreciated.
Programming the micro isn't as big of a problem as
Hi Chris,
I doubt very many groups use tone pages for non-emergency,
informational messages like the one you mentioned (To all TVARC
members, we will be holding our monthly meeting and swap shop on March
20, at the Mcdonalds on I-20 in Terrell. We will start at 5:00).
One of the things a
Hi Mike,
I'm not as familiar with the ACC or others, but the Scom has a single
audio tone source.
The 5K, 6K and 7K had one single-tone generator. The 7330 has three
dual-tone generators, one for each port.
There were pagers that used 1+1, ones that used 5 quick tones, ones
that used a
Hi Chris,
We are interested in having such a setup, but need to know if anyone
else is doing it? If so, how are you sending the tones for the pager
and such.
(A disclosure: My company used to make the 7K controller that several
folks mentioned in their responses. Its replacement, the 7330, also
Hi Ed,
Thanks for the info. One of the items on our to-do list is see how our
particular software scheme can be changed to handle this need.
73,
Bob
-Original Message-
From: Ed Yoho [EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Sent: Sat, 19 May 2007 4:51 pm
Subject: Re:
Hi Guys,
Our design team is following this discussion with great interest because
it'll definitely influence what we offer in the future regarding controlling
multiple sites.
I will disclose one bias, however:
When the prefix is received the prefix decoder generated a telephone
dial
Hi Ed,
Do you know if the software will accept site prefixing on a per port
basis (similar to Link-Comm or the old Palomar Telecom controllers)b
This is a make or break for many system owners that have multiple sites
interconnected.
I have always been impressed with the S-COM products
Hi Larry,
In a message dated 5/11/2007 4:23:08 PM Mountain Daylight Time,
[EMAIL PROTECTED] writes:
For those manufacturers who don't plan to be at Dayton, will they be sending
a demo unit and brochures to show off at someone's inside booth or outside
swap meet space?
We'll have a
Hi Jeff,
A duplexer is working correctly when the sensitivity of the receiver
is not
degraded when the transmitter becomes active. There are test procedures
to
check this out, but the explanation of these tests is beyond the scope
of
this article. [OK, I'll agree with him so far] However,
Hi Skipp,
Wilco. I'll contact you off-list.
73,
Bob
-Original Message-
From: [EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Sent: Sun, 22 Apr 2007 9:35 PM
Subject: [Repeater-Builder] Re: REPCO 2 watt vhf transmitter strip-
info request
Re: REPCO 2 watt vhf transmitter strip-
Hi Art,
Have you found the data you were looking for? If not, I might be able to
help. I found manuals for both the VHF and UHF Repco receivers and
transmitters
in the S-COM archives. They're referred to as the RDL series of RF Link
Devices, and apparently there were both voice and data
Hi Nate,
It's a road full of potholes.
Yes, repeater controllers can be made to control HF rigs, antenna
rotors, weather stations, and all kinds of simplex and duplex phone
patches in addition to the existing load of repeaters, remote bases,
and links. But it's a real job given the number of
Hi Doug,
Could anyone point me in the direction of a simple circuit which will
facilitate the muting or suppression of a 1750 hz tone on the received
audio.
Interesting question!
Simple? Maybe not. But it can be done (we design and manufacture base
station controllers that are compatible with
Hi Skipp,
What's your satisfaction level with the Norcom notch? A spec of +/-0.1%
BW means only 3.5 Hz of BW at the -40 dB points at 1750 Hz. And that's
for a tunable product, so you'd have to tune it dead on to get just 40
dB of notch. The users' generators would also have to be very accurate
Hi Gary,
Doing what, tone encode/decode or using Norcom notches?
Bob
-Original Message-
From: [EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Sent: Tue, 3 Apr 2007 11:35 AM
Subject: RE: [Repeater-Builder] Re: Tone filter
Motorola, GE, Vega and many others have been doing it
Hi Skipp,
Understood.
I'm coming in at a slightly different angle because our job was to
build dial-access base station controllers that could be installed and
accessed anywhere in North America regardless of phone line quality.
Decoding and notching F1 and F2 sequences from all brands of
Hi Vern,
In this instance, the analog delay module came out of an S-Com 5000
controller; and the contributor told me what the pinouts were supposed
to be. Although I would prefer to confirm things with proper
schematics, I have made the connecting cable according to the
information he
Hi Vern,
For reference, I have a NHRC-5 controller, ComSpec TS-32 (or TS-32P,
if any better) CTCSS module, and an S-COM analog delay line. I think
that these are the right pieces; all I think that I need is how to
hook it all up.
A caution: Please be aware that despite the fact that the
Hi Brian,
Is there a Command anywhere to warm restart a 6K?
or to say another way To Push the button remotely?
They're different. A warm start is a processor reset. It's what
happens when you remove power and then restore it. Although a warm
start forces some minor initializations, your
Hi Skipp,
The original ACC Repeater controllers had the... best kerchunk
software. I tried for years to nag a few controller mfgrs to
include the original ACC style kerchunk filter option and they
all seem to miss the point and built the classic delayed tx
mess.
Download the document that
Hi Mike,
I'd like to see a controller that has enough in it that all you need
to interface
to is discriminator audio and modulator audio. On the receive side it
could
have a Micor-type squelch and a de-emphasis network built with 1%
parts.
On the transmit side it has pre-emphasis and feeds
Hi NJ,
... The solution seems to be to run flat audio within
the controller, ...
I couldn't agree more. Coming from the commercial two-way world,
this is how we do everything, but I do understand why some repeater
builders want to go the other way. I just wouldn't call it flat
audio - it's just
Hi Jeff,
Bottom line: limiting after preemphasis results in a reduction in the
noise-limited dynamic range at higher frequencies; that's a natural
byproduct of a process which originated in the user's radio. The
repeater,
following the same preemphasis/deemphasis curve as the user's radio,
has
Guys, an observation:
I hope the discriminator equals flat folks appreciate the mess
they've created with our lexicon.
Rodney has now been forced to say it like this:
This chart shows pin 11 as Filtered Audio Out which is de-emphasised
audio
pre-volume control. If you want straight
Hi,
Huh???
De-emphasized audio has a tilted frequency response BY DEFINITION!
No, de-emphasized audio has a flat response in our system. It's tilted
if you feed flat audio into a de-emphasis circuit -- but we never do
that. We always feed pre-emphasized audio into a de-emphasis circuit,
thus
Hi Shorty,
Flat Audio through a repeater simply means that the repeater
does not mess with the audio through-put.
I know that's what you and others mean, but that's not what learners
see. More and more listmembers are routinely talking about flat audio
from the discriminator, and I know they
Howdy,
You make my point. You say Our system You are a controller guy.
Your controller is your perspective. But that is actually a device
perspective.
Sure, I'm a controller guy, and since S-COM is going headlong into the
multiport controller biz, I have a vested interest in this
Mike and all,
Here's another item to add to the capacitor page. It's for those who've
wondered why an X7R ceramic cap is better'n a Z5U ceramic cap...
73,
Bob, WA9FBO
_www.scomcontrollers.com_ (http://www.scomcontrollers.com)
EIA Three Digit TC Codes for Ceramic Capacitors
Low
Laryn,
Might be 470 uH.
73,
Bob
-Original Message-
From: [EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Sent: Wed, 21 Feb 2007 9:55 AM
Subject: [Repeater-Builder] Inductor? Value
Wow, thanks for the help on the capacitor value.
In the same circuit is a resistor look-alike
Most manufacturers use the three-digit code system now, where 100 = 10
pF and 470 = 47 pF (third digit = 0 = no zeroes).
Bob
-Original Message-
From: [EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Sent: Wed, 21 Feb 2007 9:48 AM
Subject: Re: [Repeater-Builder] Re: Capacitor value
Hi Skipp,
It looks great Bob... can't wait to see when they become
available for sale. I'll probably be right there at the
order desk when they're ready. The nice part about you
repeater controller guys is there's almost no work involved to make the
box and write the software...
At last, photos and hard data on the 7330 athttp://www.scomcontrollers.com!Please
check out the New Directions paper as well as theother new material.
It discusses the philosophies behind this new line ofcontrollers and
helps show why the project has taken so much
well-spenttime!We'll
Hi Russ,
pretty neat pictures... Mule on the
attack.
Part urban legend -- the pix are real, but the mule didn't kill the cat (http://www.snopes.com/photos/animals/mulelion.asp).
73,
Bob, WA9FBO
Member, Rocky Mountain LongEars Assoc.
YAHOO! GROUPS LINKS
Hi Chas,
Shouldn't the touch tone pad tone be set at the maximum deviation or
nearly so?
No, and here's the explanation:
1. The pre-emphasis in your transmitter causes the tone with the higher
freq to deviate more than the other tone(forexample, the 1477 Hz
tone will deviate more
Hi Mike,
The 6K and 7K have been discontinued, but the feature will be
kept in the new 7330 controller. It's been a while
since I looked, how's the timeframe coming for the release of the 7330
Bob?
Our new slogan: Dayton or bust!
73,
Bob, WA9FBO
YAHOO!
Hi Chris,
can one remotely activate a repeater without tones?
Say: click PTT three times within 3 seconds and repeater is
up. click PTT four times within 3
seconda dn repeater is down
The S-COM 6K and 7K repeater controllers have hadthis feature for
many yearsdue toour involvement
Hi Juan,
Your e-mail address was bouncing messages back to Yahoogroups so it
delisted you. I've reinstated your membership.
The 7K can operate two repeatersby tying a second repeater to the
link port. It'll handle the CORs and PTTs,sendmessages to the proper
TX (if the messages are
Hi Matthew,
I powered down the Mastr Pro receiver, noise still
there,only thing left was the cat controller, powered it down and
noise isgone. This noise was heard over a large frequency spread
in theaircraft band on the SM. Could it be possible that the
controllercould be the
Hi Bruce,
I have a C3I audio connected to a Cat 300dx.
As you increase the delay there a hiss that
is heard. If you turn the delay off, the hiss is
silent. Any Ideas?
That audio delay module uses two cascaded Reticon RD5108 bucket-brigade
audio delay chips. Bucket-brigade technology
Hi Guys,
We putthree white papers on the S-COM website (www.scomcontrollers.com) written by
Virgil, W0INK, that follow up on some of the discussionsabout PM and FM on
these lists.
If you're in the mood for some interesting technical reading, fill your
coffee cup and take a look at:
WB6YMH wrote:
Since we into nostalga what's the earliest date of a microprocessor based repeater or remote base controller? I built a Z80 based controller during 79 and 80 that ended up with 6 K of assembly language and 4 radio ports.
Ibuilt the147.300 WR9AIN repeater in New Holstein, WI in
Hi Kevin,
I am installing a Comm Spec SS-32 encoder in a Micorrepeater. I am using a logic output from an S-Com 5Kcontroller to key the ground connection to the encoderwhenever the RX COR is active. I need to do this tobe able to link into another system.My problem is when ever the encoder
Hi Bob,
I didn't want to confuse a highly technical topic with the FM/PM thingagain. Personally, I find it easier to think of angle modulation in terms of frequency as opposed to phase.
Sure, me too - - maybe most of us on the list. That's probablybecause we'reused to thinking in terms of
Hi Guys,
Very interesting site: http://www.mbay.net/~wb6nvh/Motadata.htm
73,
Bob, WA9FBO
Yahoo! Groups Links
To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/
To unsubscribe from this group, send an email to:[EMAIL PROTECTED]
Your use of
Hi Joe,
At some point in DSP, audio processing, synthesis, etc-all thrown into a bag and each manipulated withnumbers or programming, we sort of lose base with whatwe are doing. We could create AM, FM, PM, SSB, PSK,FSK, what have you.
And as amateurs and technical people, it'd be good if we
Hi Steve,
Does anyone think it would be feasible or practical to modify the TA-51 to implement an LC phase modulator? Just how easy or how difficult might that be?
You coulduse a varicap, a tunable inductor, and a capacitor to build acircuit that'sresonant at the crystal frequency, and
Hi Joe,
You want us to believe that PM is why we Pre-emp FM.
Yup. It's a PM world, and you must make your FM equipment work in that world.
That's simply not the case. This is not supported byanything I have ever seen or read, only by you.
These areconclusions we drewfrom old documents from
Hi Joe,
Bob (S-Com Bob), would it be a fair statement to say that traditionally,transmitters have generally been PM (either true PM or emphasized FM),but receivers have been FM all along? I base this on your last post.
Yes, absolutely!
To further state the case, assume that there are two
Hi Joe,
In one universe, all hams use phase modulators and phase demodulators. The terms 'preemphasis' and 'deemphasis' are unheard of. The whole system has flat response. Since their phase demodulators track their phase modulators, the hams communicate via voice and data over their PM
Hi Laryn,
It was just over a year ago that there was a long thread about FM and PM. Someone posted a link to a short magazine article (Ham Radio, it seems it was, but not sure) that shed light on the fact that PM was the first popular method of modulation for land mobile use. I've searched
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