Thanks, David.
This is exactly the info I need.
Tom Behler: KB8TYJ
-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of David W Wood
Sent: Tuesday, June 30, 2015 6:54 PM
To: [log in to unmask]
Subject: Re: Yet Another Update On RV DXCC Antenna Situation
TOM
THE .TXT IS AS BELOW:
Audible Transmitter Output Monitor (ATOM) Instruction Manual
Description:
6/4/2011
ATOM is a simple tuning aid for blind or low-vision hams who cannot access
an internal or external power meter. For stations that have initially been
installed correctly, ATOM will give a recognizable audible alert if
something is preventing a transmitter from putting out full power, and
causes your CQ's to go unheard. ATOM will catch most common oversights such
as not setting VOX correctly or not activating an automatic antenna tuner,
and also catch more serious problems such as damage to feedlines or antennas
when the transmitter has circuitry to limit RF output due to high VSWR.
If you cannot read a power meter or other qualitative means to know that
output is being generated, use ATOM. You'll find that ATOM gives you a
very information-rich indication of the RF activity on your feedline,
building confidence that all is working as intended.
ATOM is not of course an VSWR meter. While such meters give you more
information, they are also slightly more complicated to operate, and much
more expensive. Their capability is more than is needed to answer the
question "is my transmitter continuing to work as well as it did when it was
initially installed?"
ATOM is connected between the transceiver and feedline (or tuner, if
external). It has two SO239 connectors, and either one may be used as the
input. When turned on, ATOM sounds a tone whose pitch is related to the
transmitted power. Much information can be gleaned from its audible signals,
such as how the power varies while an automatic antenna tuner searches for
the best match.
ATOM will work well with transceivers having built-in tuners feeding
antennas such as G5RVs, or others with VSWRs less than approximately 4:1, or
for use with remote antenna tuners connected to any type of antenna. It
works between 1.8 MHz and 54 MHz, at power levels from 1 watt up to around
150 watts.
When used with a remote antenna tuner such as an SGC234 mounted at the feed
point of the antenna, ATOM will emit a series of warbling tones while the
tuner's program matches the 50-ohm coax to the transmitter/tranceiver. A
steady tone is emitted once a good match is found, and subsequent
transmissions on the same frequency will yield an immediate steady tone
because the tuner will have previously memorized the best settings. ATOM can
also be use with external autotuners also in the ham shack, but these units
usually make enough relay noise while working as to make for less need for
ATOM. However ATOM might be enlightening when the tuner is trying to
achieve a match close to its limits, if the tuner gives up, and there's no
output!
The circuitry inside ATOM senses the RF voltage on the feed line, and uses
it to control a voltage-controlled oscillator (VCO). Unlike a VSWR meter,
ATOM is responsive to both forward and reverse power, but still gives a very
good idea of what is happening on the feedline. When a transmitter is
matched to 50 ohms, it responds to one watt signals with a a buzz at
approximately 40 Hz. For a matched 100 watt signal, the pitch is around
1KHz, increasing to around 1.5 KHz at 54 MHz. The front end of ATOM is safe
for RF voltages up to around 700 volts peak, so its 150W rating for VSWR's
less than 4:1 is conservative.
The power switch is "on" when flipped towards the speaker grille. The
batteries will discharge after about 500 hours of operation with ATOM turned
on but with no RF present, so the switch should be turned off when ATOM is
not in use. ATOM should not be used as a side tone monitor since that would
shorten the battery life to several hundred hours. In normal use the
batteries should last their shelf life, approximately seven years.
How I use ATOM:
* The supplied PL-259 coupler is used to connect one ATOM connector to my
Kenwood TS440SA.
* My feedline cable is connected from the other ATOM connector to my remote
SGC234 antenna autotuner.
* The transmitter is set to the frequency I want to use, in the CW mode.
* The Kenwood is set to work straight through (i.e., not using it's internal
tuner).
* ATOM is turned ON.
* Transmitter power is applied. ATOM will emit a high-pitch tone. If it
remains steady, the tuner is matched, and you're ready to go. If the tone
takes on a warbling or variable-pitch aspect, the tuner is attempting to
achieve a match, and the tone may cover a wide range of pitches but usually
settles down to a steady tone within 10 to 20 seconds.
* We're ready to go after we have a match, and ATOM can be turned off, which
I recommend when using phone modes as its tone will get into the microphone.
Changing the Batteries:
ATOM uses four triple A batteries. When their voltage drops and they need
to be replaced, the first thing you will notice is that ATOM's audio volume
drops precipitously. This happens at approximately 50% voltage.
To change the batteries, remove the four flat-head screws in the corners of
the box. Replace the four batteries as a set, with the negative side of the
batteries against the springs in the battery holder.
Troubleshooting
This device is really very simple and not much can go wrong with it. But if
you think the device is not responding when it should, you can try these
things:
Make sure it's on! It's powered when the switch is toward the speaker grill.
* Make sure it has fresh batteries. See the procedure above to change them.
Connect the plus side of a 9-volt battery to the center pin of either SO239
socket, with the minus side connected to the case (ground). When ATOM is on
and has fresh batteries, you'll hear a rapid ticking sound.
Contact Information
If you need to contact the manufacturer of this device, send email to
[log in to unmask] or call 650-386-6286.
Specifications:
Frequency coverage: 1.8 MHz - 54 MHz.
RF power limit: 150 watts max. for 50-ohm coax line with VSWR <4:1.
Pitch range: 1 Hz (pulses) through several KHz (tones), depending on RF
voltage Pitch vs. feedline voltage, same band: monotonic Typical (not
specified) tone pitches:
0W: (no tone output)
1W matched: 30-40 Hz
10W matched: 350 Hz for 1.8 MHz, 575 Hz for 54 MHz 100W matched: 1 KHz for
1.8 MHz, 1.5 KHz for 54 MHz
Power: 4 internal AAA alkaline batteries (included) Battery Drain, no
signal: <2 ma.
Battery drain, typical signals: 2-25 ma.
Battery expected lifetime with typical use: approaching shelf life
Input/output connections: SO-239 coax
Dimensions: 1.2" x 2.4" x 4.4"
Supplied accessory: PL-259 M-M coupler
Theory, and word description of schematic:
ATOM measures the peak RF voltage on a feedline and provides reassurance
that an amateur radio transmitter is operating correctly and actually
putting out power. The transmitter's feedline is routed through ATOM's
housing. ATOM then uses a voltage-controlled oscillator (VCO) U1 to generate
an audible pitch proportional to the signal level on the feedline. ATOM's
VCO uses an LM555 timer IC, U1, packaged as an 8-pin DIP.
The input and output SO239 coax sockets are grounded to the metal case. The
minus side of the 6 volt battery is also grounded, and the positive side is
fed through a SPST toggle switch S1 to provide Vcc to the LM555 IC U1
oscillator.
Pin 1 of the VCO U1 is grounded, and pins 4 and 8 are connected to Vcc. Pins
2 and 6 are connected together and to the timing capacitor C1, a 0.1uF 10%
dip ceramic capacitor, whose other end is grounded. A 4.99K 1/4W 1%
discharge resistor R2 is connected between pin 6 and the discharge pin 7.
Pin 3 connects to a 32-ohm speaker (SPKR1), whose other side is connected to
Vcc.
A jumper wire connects the center pins between the SO239 connectors and to
the anode of D1 on the circuit board. D1 is the first in a string of eight
1N4148 diodes (D1-D8) used to sample the RF voltage on the feedline. The
rectified voltage, which can reach several hundred volts, is fed from the
cathode of the last diode D8 through a 100K 1W metal film resistor R1, to
U1's pin 7.
In operation, voltages on the feedline are rectified by the diodes and used
to charge the timing capacitor C1 by sending current through resistor R1.
When the voltage on the capacitor reaches a certain value, the timer U1
triggers, and causes its pin 7 to be grounded, which discharges C1 through
R1. When RF is present, this process repeats itself continually. Each time
U1 cycles, a pulse is produced on pin 3, which is heard in the speaker. How
fast these cycles repeat depends on the voltage on the feedline. They will
repeat several tens of times per second for single-digit power-levels, and
many hundreds of times per second for powers of 100 watts or more.
Schematic:
Mike Kiethley
[log in to unmask]
1
ATB
David W Wood
-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Tom Behler
Sent: Tuesday, June 30, 2015 11:20 PM
To: [log in to unmask]
Subject: Re: Yet Another Update On RV DXCC Antenna Situation
Butch or anyone:
I'd appreciate the info page on the Atom.
I've heard of it, but just don't recall the details.
For now, I think I'm going to play with my little MFJ Versatuner, and my
TW1.
Pulling the TW1 out of my home station setup every time we go to the RV will
be a bit of a pain, but it will help to provide me with a better idea of
exactly what I'm working with out there, before I consider spending any more
money.
I also contacted a friend today, who agreed to bring an MFJ antenna analyzer
out to the camp site the week-end after next, so that should also help.
Tom Behler: KB8TYJ
-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Butch Bussen
Sent: Tuesday, June 30, 2015 4:57 PM
To: [log in to unmask]
Subject: Re: Yet Another Update On RV DXCC Antenna Situation
The noise bridge will work, although I've found a little tricky adjusting a
tuner, works good on a screw driver. Also there is the a t om box, pitch
rises on audio output, doesn't read swr, but max out should work.
I can find you the page if you need it. I think the cost is around $90
73
Butch
WA0VJR
Node 3148
Wallace, ks.
On
Mon, 29 Jun 2015, Tom Behler wrote:
> Thanks, Lou.
>
> As I indicated in my last post, I hate to have to tear things apart to
> take the TW1 to the RV every time I go out there, so I'm looking at
> other options. Perhaps one of those MFJ noise bridges.
>
> Tom Bbehler: KB8TYJ
>
>
> -----Original Message-----
> From: For blind ham radio operators
> [mailto:[log in to unmask]]
> On Behalf Of Lou Kolb
> Sent: Monday, June 29, 2015 4:23 PM
> To: [log in to unmask]
> Subject: Re: Yet Another Update On RV DXCC Antenna Situation
>
> Tom,
>
> i'd bring the Tw1 out there with you and just use the manual tuner.
> And, it may sound fool-hearty, but I think I would even have tried to
> run it on 20 meters despite the high SWR, It's doubtful you'd hurt
> anything with today's foldback circuitry and It might've given you
> more contacts. However, most reports I've heard seem to confirm what
> you've said, that 40 was the place to be. Anyway, the fact that the
> alpha-delta guy recommends running it as is, also indicates you should
just try it and see what it does. Good luck.
> Lou WA3MIX
> Lou Kolb
> Voice-over Artist:
> Radio/TV Ads, Video narrations
> Messages On-hold:
> www.loukolb.com
> ----- Original Message -----
> From: "Tom Behler" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Monday, June 29, 2015 2:42 PM
> Subject: FW: Yet Another Update On RV DXCC Antenna Situation
>
>
>> Hi, everyone.
>>
>>
>>
>> For whatever reason, my internet connection was acting really weird
>> at the RV yesterday evening, so I don't know if my original e-mail
>> made it to the list.
>>
>>
>>
>> Usually, I get at least some responses to my various posts, so I'm
>> really wondering if it got lost in cyber space somewhere.
>>
>>
>>
>> If anyone wishes to comment on my thoughts below regarding my DXCC
>> antenna situation out at the rv, I'd be very interested.
>>
>>
>>
>> Again, see the e-mail below.
>>
>>
>>
>> Tom Behler: KB8TYJ
>>
>>
>>
>>
>>
>> From: Tom Behler [mailto:[log in to unmask]]
>> Sent: Sunday, June 28, 2015 8:31 PM
>> To: [log in to unmask]
>> Subject: Yet Another Update On RV DXCC Antenna Situation
>>
>>
>>
>> Hello, again, everyone.
>>
>>
>>
>> Well, on kind of a whim this afternoon, I wrote to Don Terrell of
>> Alpha Delta Engineering about my situation with the Alpha Delta DXCC
>> HF antenna here at the RV. I explained the installation to him, and
>> what I thought might be contributing to my problems.
>>
>>
>>
>> Here's what he said:
>>
>>
>>
>> Hi Tom, I have read your e-mail carefully. I think the RV roof, being
>> metal, AND the 60 degree angle would be the "bad guys". Also, if the
>> wires are within about 3-4 ft. from tree branches that will cause a
>> coupling problem as well. In this case, just use a wide range tuner
>> and leave it as is. the "on air' performance should be fine anyway.
>>
>>
>>
>> TNX and 73,
>>
>>
>>
>> Don, W8AD
>>
>>
>>
>> So, now, this brings me to another thought:
>>
>>
>>
>> I have an old MFJ 901B manual versatuner that is not being used for
>> anything right now.
>>
>>
>>
>> Could I use that to basically tune the antenna, using receive noise
>> as my indicator, and then just touch things up with the internal
>> auto-tuner in the TS480?
>>
>>
>>
>> I have always heard that doing this would cause the tuners to work
>> against each other, which could create real problems, but I never
>> knew whether that was true or not.
>>
>>
>>
>> Of course, I do have an LDG TW1 talking SWR/watt meter at the home
>> qth, but hate to tear things apart to use it during the relatively
>> short times when we are camping.
>>
>>
>>
>> Does anyone have any wisdom on this latest idea?
>>
>>
>>
>> I have also asked the question to Don Terrell himself.
>>
>>
>>
>> Tom Behler: KB8TYJ
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
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