Quantcast

KX3 Receive Performance Below 1500 kHz

classic Classic list List threaded Threaded
10 messages Options
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

KX3 Receive Performance Below 1500 kHz

Edward R Cole
If this is true then the spec on page 51 of the KX3 manual is very
misleading where is states:
"310 kHz - 32 MHz and 44-54 MHz..."

I was looking forward to using the KX3 on the new 630m Ham Band
recently approved by WRC-2012:
472-478 KHz.  The K3 operates down to 490 KHz but no lower so
unusable on the new ham band.  The KX3 "appeared" to be the first
commercially mfd radio able to operate down there.  If not then this
is a BIG missed opportunity.

I use a Clifton Labs Z-10020 MW BC Band Reject filter (540-1700 KHz)
which rejects signals inside that band.  Signals seen at -50 dBm are
reduced to the the -110 dBm noise floor, whereas the signals below
540-KHz are unaffected below about 515 KHz.  I have used it with the
K3 and my SDR-IQ (which tunes to 500-Hz).

There was discussion last fall that the KX3 might be capable of
transmitting on 630m.
I would like the official word on this before publishing my paper
reviewing the KX3 at MUD-2012.

630m will remain the province of the "experimenter" if no commercial
"shelf-ready" equipment is available.


73, Ed - KL7UW
I run 100w into a 43x122 foot inverted-L on 600m under the license WD2XSH/45.
------------------
Date: Sat, 7 Jul 2012 08:15:31 -0500 (GMT-05:00)
From: Mike Morrow <[hidden email]>
Subject: [Elecraft] KX3 Receive Performance Below 1500 kHz
To: [hidden email]
Message-ID:
         <[hidden email]>

Content-Type: text/plain; charset=UTF-8

A discussion of KX3 MF lack of sensitivity recently took place
on the KX3 list.  The KX3 should not be considered really
usable below about 1500 kHz, as Wayne explsined:

---- Original Message (from KX3 list)

 > I thought there was some advantage to AM BCB reception
 > to be had with the KXAT3.

If a KXAT3 is installed, harmonic images are attenuated,
but this has little effect on signal strength.

 > Why wouldn't the T/R PIN diodes be as well protected by
 > high pass filtering that rolled off below 400 kHz rather
 > than 1500 kHz

The carrier lifetime of the diodes is roughly 1.5 microseconds.
This means that strong signals at the low end of the broadcast band
could cause IMD (IP2) if not attenuated. The HPF provides
about  20-30 dB of rolloff by this frequency, ensuring that
this isn't a problem. The KX3 is optimized for ham-band use
so this is entirely appropriate.

Wayne


73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
EME: 50-1.1kw?, 144-1.4kw, 432-QRT, 1296-?, 3400-?
DUBUS Magazine USA Rep [hidden email]
"Kits made by KL7UW" http://www.kl7uw.com/kits.htm
======================================
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: KX3 Receive Performance Below 1500 kHz

wayne burdick
Hi Ed,

The KX3's spec also says, "Note: Sensitivity decreases gradually below  
1.5 MHz due to protective high-pass filtering...." We did this to  
ensure that the PIN diodes in the T/R switch are protected. A fairly  
large amount of attenuation is required by the time you get down to  
500 kHz or lower.

We did do some transmit tests in the 470 kHz range. We can easily get  
+10 or possibly +20 dBm output at these frequencies, but you'd need an  
external filter/amplifier to obtain useful transmit power output.  
Given that, I would think that an external receiving converter that  
shifted the 0-1 MHz range up to 7-8 MHz on the KX3 would also be a  
good solution. The KX3 has transverter bands that can be set up for  
this application, allowing the VFO to read correctly when on this  
band. The ACC2 GPIO pin could be used to turn the external converter  
on/off.

The K3 has the same high-pass filtering in the main antenna path as  
the KX3. But the K3 also provides a way to bypass the filter, by using  
the KXV3's RX ANT input (or the XVTR input).

73,
Wayne
N6KR


On Jul 8, 2012, at 12:22 AM, Edward R. Cole wrote:

> If this is true then the spec on page 51 of the KX3 manual is very
> misleading where is states:
> "310 kHz - 32 MHz and 44-54 MHz..."
>
> I was looking forward to using the KX3 on the new 630m Ham Band
> recently approved by WRC-2012:
> 472-478 KHz.  The K3 operates down to 490 KHz but no lower so
> unusable on the new ham band.  The KX3 "appeared" to be the first
> commercially mfd radio able to operate down there.  If not then this
> is a BIG missed opportunity.
>
> I use a Clifton Labs Z-10020 MW BC Band Reject filter (540-1700 KHz)
> which rejects signals inside that band.  Signals seen at -50 dBm are
> reduced to the the -110 dBm noise floor, whereas the signals below
> 540-KHz are unaffected below about 515 KHz.  I have used it with the
> K3 and my SDR-IQ (which tunes to 500-Hz).
>
> There was discussion last fall that the KX3 might be capable of
> transmitting on 630m.
> I would like the official word on this before publishing my paper
> reviewing the KX3 at MUD-2012.
>
> 630m will remain the province of the "experimenter" if no commercial
> "shelf-ready" equipment is available.
>
>
> 73, Ed - KL7UW
> I run 100w into a 43x122 foot inverted-L on 600m under the license  
> WD2XSH/45.
> ------------------
> Date: Sat, 7 Jul 2012 08:15:31 -0500 (GMT-05:00)
> From: Mike Morrow <[hidden email]>
> Subject: [Elecraft] KX3 Receive Performance Below 1500 kHz
> To: [hidden email]
> Message-ID:
>         <[hidden email]
> >
>
> Content-Type: text/plain; charset=UTF-8
>
> A discussion of KX3 MF lack of sensitivity recently took place
> on the KX3 list.  The KX3 should not be considered really
> usable below about 1500 kHz, as Wayne explsined:
>
> ---- Original Message (from KX3 list)
>
>> I thought there was some advantage to AM BCB reception
>> to be had with the KXAT3.
>
> If a KXAT3 is installed, harmonic images are attenuated,
> but this has little effect on signal strength.
>
>> Why wouldn't the T/R PIN diodes be as well protected by
>> high pass filtering that rolled off below 400 kHz rather
>> than 1500 kHz
>
> The carrier lifetime of the diodes is roughly 1.5 microseconds.
> This means that strong signals at the low end of the broadcast band
> could cause IMD (IP2) if not attenuated. The HPF provides
> about  20-30 dB of rolloff by this frequency, ensuring that
> this isn't a problem. The KX3 is optimized for ham-band use
> so this is entirely appropriate.
>
> Wayne
>
>
> 73, Ed - KL7UW, WD2XSH/45
> ======================================
> BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
> EME: 50-1.1kw?, 144-1.4kw, 432-QRT, 1296-?, 3400-?
> DUBUS Magazine USA Rep [hidden email]
> "Kits made by KL7UW" http://www.kl7uw.com/kits.htm
> ======================================
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: KX3 Receive Performance Below 1500 kHz

Edward R Cole
Wayne,

Thanks for the quick reply.  I have also determined that there is
reception down to 310-KHz when I use an antenna cut for 500-KHz.  My
first test was quick and used my 80m inverted-V which resulted in
nothing being heard (maybe I did not have a good connection; it was
just a quick look).  I saw useful receive levels which would lead me
to think use of my Clifton BC band  reject filter ahead of a preamp
tuned for 470-KHz would probably restore good sensitivity without
subjecting the KX3 to overloading signals from the BC band (based on
what I see using this filter with the K3 and the SDR-IQ).

+10 dBm is quite sufficient for my transmit amplifier (a converted
100w NDB transmitter).  I drive it with under 1mw direct from the K3
running in TEST mode output of the transverter output jack.  I have
built a low-pass filter for 510-KHz which can be used for
transmitting (rated several hundred watts).  WRC-12 stipulates ham
output on the 630m band will not exceed 1w ERP (and no more than 5w
ERP if permitted by certain national regulatory agencies).  The ARRL
Experimental Group was licensed to run up to ERP=20w;  my 100w
transmitter produces 4.15w ERP with my inverted-L antenna.  So
considering the low efficiency of antennas that hams would use one
may only need something like 20w RF output.  That is +43 dBm implying
the need for about 30-dB transmit amplifier for the KX3.  Relatively
easy to do at this frequency (even a tube-type amp ckt drug out of an
old 1960-70 manual would work).  Some of our experimenters have had
success converting stereo audio amplifiers into 500-KHz amplifiers
with suitable change of input/output transformers and bypassing changes.

Of course using a transverter is an option but that is a
builder-experimenter option, at present.  I actually built one for
translating 10.4xx to 4xx KHz by use of a SBL-1 mixer and my 10-MHz
OCXO station freq. reference source.  The K3 will operate in test
mode for running at 10.472-10.478 KHz.  For other radios one would
chose a ham band such as 80m or 40m to translate down.

I will do some testing with my KX3 on transmitting at 470-KHz and
have in mind a transistor amp to provide 25w (which I may eventually
make if there is a market).  Ham radio use of 472-478 KHz will
require FCC action to happen in the USA.  WRC-12 approves use after
Jan 1, 2013.

73, Ed - KL7UW

At 07:49 AM 7/8/2012, Wayne Burdick wrote:

>Hi Ed,
>
>The KX3's spec also says, "Note: Sensitivity decreases gradually below
>1.5 MHz due to protective high-pass filtering...." We did this to
>ensure that the PIN diodes in the T/R switch are protected. A fairly
>large amount of attenuation is required by the time you get down to
>500 kHz or lower.
>
>We did do some transmit tests in the 470 kHz range. We can easily get
>+10 or possibly +20 dBm output at these frequencies, but you'd need an
>external filter/amplifier to obtain useful transmit power output.
>Given that, I would think that an external receiving converter that
>shifted the 0-1 MHz range up to 7-8 MHz on the KX3 would also be a
>good solution. The KX3 has transverter bands that can be set up for
>this application, allowing the VFO to read correctly when on this
>band. The ACC2 GPIO pin could be used to turn the external converter
>on/off.
>
>The K3 has the same high-pass filtering in the main antenna path as
>the KX3. But the K3 also provides a way to bypass the filter, by using
>the KXV3's RX ANT input (or the XVTR input).
>
>73,
>Wayne
>N6KR
>
>
>On Jul 8, 2012, at 12:22 AM, Edward R. Cole wrote:
>
>>If this is true then the spec on page 51 of the KX3 manual is very
>>misleading where is states:
>>"310 kHz - 32 MHz and 44-54 MHz..."
>>
>>I was looking forward to using the KX3 on the new 630m Ham Band
>>recently approved by WRC-2012:
>>472-478 KHz.  The K3 operates down to 490 KHz but no lower so
>>unusable on the new ham band.  The KX3 "appeared" to be the first
>>commercially mfd radio able to operate down there.  If not then this
>>is a BIG missed opportunity.
>>
>>I use a Clifton Labs Z-10020 MW BC Band Reject filter (540-1700 KHz)
>>which rejects signals inside that band.  Signals seen at -50 dBm are
>>reduced to the the -110 dBm noise floor, whereas the signals below
>>540-KHz are unaffected below about 515 KHz.  I have used it with the
>>K3 and my SDR-IQ (which tunes to 500-Hz).
>>
>>There was discussion last fall that the KX3 might be capable of
>>transmitting on 630m.
>>I would like the official word on this before publishing my paper
>>reviewing the KX3 at MUD-2012.
>>
>>630m will remain the province of the "experimenter" if no commercial
>>"shelf-ready" equipment is available.
>>
>>
>>73, Ed - KL7UW
>>I run 100w into a 43x122 foot inverted-L on 600m under the license
>>WD2XSH/45.
>>------------------
>>Date: Sat, 7 Jul 2012 08:15:31 -0500 (GMT-05:00)
>>From: Mike Morrow <[hidden email]>
>>Subject: [Elecraft] KX3 Receive Performance Below 1500 kHz
>>To: [hidden email]
>>Message-ID:
>>
>><[hidden email] >
>>
>>Content-Type: text/plain; charset=UTF-8
>>
>>A discussion of KX3 MF lack of sensitivity recently took place
>>on the KX3 list.  The KX3 should not be considered really
>>usable below about 1500 kHz, as Wayne explsined:
>>
>>---- Original Message (from KX3 list)
>>
>>>I thought there was some advantage to AM BCB reception
>>>to be had with the KXAT3.
>>
>>If a KXAT3 is installed, harmonic images are attenuated,
>>but this has little effect on signal strength.
>>
>>>Why wouldn't the T/R PIN diodes be as well protected by
>>>high pass filtering that rolled off below 400 kHz rather
>>>than 1500 kHz
>>
>>The carrier lifetime of the diodes is roughly 1.5 microseconds.
>>This means that strong signals at the low end of the broadcast band
>>could cause IMD (IP2) if not attenuated. The HPF provides
>>about  20-30 dB of rolloff by this frequency, ensuring that
>>this isn't a problem. The KX3 is optimized for ham-band use
>>so this is entirely appropriate.
>>
>>Wayne
>>
>>
>>73, Ed - KL7UW, WD2XSH/45
>>======================================
>>BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
>>EME: 50-1.1kw?, 144-1.4kw, 432-QRT, 1296-?, 3400-?
>>DUBUS Magazine USA Rep [hidden email]
>>"Kits made by KL7UW" http://www.kl7uw.com/kits.htm
>>======================================
>>______________________________________________________________
>>Elecraft mailing list
>>Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>Help: http://mailman.qth.net/mmfaq.htm
>>Post: mailto:[hidden email]
>>
>>This list hosted by: http://www.qsl.net
>>Please help support this email list: http://www.qsl.net/donate.html


73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
EME: 50-1.1kw?, 144-1.4kw, 432-QRT, 1296-?, 3400-?
DUBUS Magazine USA Rep [hidden email]
"Kits made by KL7UW" http://www.kl7uw.com/kits.htm
======================================
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: K3/KX3 MF/LF Transverter

KXBill
In reply to this post by wayne burdick

Wayne:
An Elecraft Transverter for below 510 kHz would be well received, world wide.  I  guess the number of participants would be rather low to start with but interest would increase with the availability of such an item.  A poll of the amateur market would give a good indication of interest.  If the numbers aren't there to warrant such venture, then maybe one of the small kit-providers might pick up the banner.
Presently, I see two potential customers; KL7UW and myself.  How's that for a start? ;)
73
de Bill-w7kxb
. .




> From: [hidden email]
> To: [hidden email]
> Date: Sun, 8 Jul 2012 08:49:25 -0700
> CC: [hidden email]
> Subject: Re: [Elecraft] KX3 Receive Performance Below 1500 kHz
>
> Hi Ed,
>
> The KX3's spec also says, "Note: Sensitivity decreases gradually below  
> 1.5 MHz due to protective high-pass filtering...." We did this to  
> ensure that the PIN diodes in the T/R switch are protected. A fairly  
> large amount of attenuation is required by the time you get down to  
> 500 kHz or lower.
>
> We did do some transmit tests in the 470 kHz range. We can easily get  
> +10 or possibly +20 dBm output at these frequencies, but you'd need an  
> external filter/amplifier to obtain useful transmit power output.  
> Given that, I would think that an external receiving converter that  
> shifted the 0-1 MHz range up to 7-8 MHz on the KX3 would also be a  
> good solution. The KX3 has transverter bands that can be set up for  
> this application, allowing the VFO to read correctly when on this  
> band. The ACC2 GPIO pin could be used to turn the external converter  
> on/off.
>
> The K3 has the same high-pass filtering in the main antenna path as  
> the KX3. But the K3 also provides a way to bypass the filter, by using  
> the KXV3's RX ANT input (or the XVTR input).
>
> 73,
> Wayne
> N6KR
>
>

     
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: K3/KX3 MF/LF Transverter

Jim Lowman
Not to rain on anyone's parade, Bill, but a couple of things
come to mind:

--  I would think it a risky business to develop a transceiver
      for a band that is not yet authorized for amateur use

--   If most of us have trouble getting an antenna going for
       160m - wow - 630m?

Just thinking out loud; not wanting to discourage anyone.

73 de Jim - AD6CW

On 7/8/2012 10:42 AM, Bill Harris wrote:
> Wayne:
> An Elecraft Transverter for below 510 kHz would be well received, world wide.  I  guess the number of participants would be rather low to start with but interest would increase with the availability of such an item.  A poll of the amateur market would give a good indication of interest.  If the numbers aren't there to warrant such venture, then maybe one of the small kit-providers might pick up the banner.
> Presently, I see two potential customers; KL7UW and myself.  How's that for a start? ;)
> 73
> de Bill-w7kxb
> . .
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: K3/KX3 MF/LF Transverter

Eric Tichansky-2
There are plenty of LF converters to homebrew from, most very
simple including those using an SA602/612.  Another is the AMRAD
LF converter, QST April 2002.  PCBs can be purchased from FAR
circuits.  I use three of those for dual RX and TX with a 14MHz
local oscillator and a K3 in transverter mode, displaying the
actual LF freq (Project: http://no3m.net/index.php?page=600m ).

There are guys in the experimental group running antennas far
smaller than most would consider. However, while a short,
minimally top-loaded (relatively speaking), heavily base loaded
antenna will be grossly inefficient, all it takes is more power
to reach the ERP level, which will be low anyways.

73 - Eric NO3M

On 07/08/12 18:48, Jim Lowman wrote:

> Not to rain on anyone's parade, Bill, but a couple of things
> come to mind:
>
> --  I would think it a risky business to develop a transceiver
>        for a band that is not yet authorized for amateur use
>
> --   If most of us have trouble getting an antenna going for
>         160m - wow - 630m?
>
> Just thinking out loud; not wanting to discourage anyone.
>
> 73 de Jim - AD6CW
>
> On 7/8/2012 10:42 AM, Bill Harris wrote:
>> Wayne:
>> An Elecraft Transverter for below 510 kHz would be well received, world wide.  I  guess the number of participants would be rather low to start with but interest would increase with the availability of such an item.  A poll of the amateur market would give a good indication of interest.  If the numbers aren't there to warrant such venture, then maybe one of the small kit-providers might pick up the banner.
>> Presently, I see two potential customers; KL7UW and myself.  How's that for a start? ;)
>> 73
>> de Bill-w7kxb
>> . .
>>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: K3/KX3 MF/LF Transverter

Edward R Cole
In reply to this post by KXBill
Jim,

Actually WRC-12 authorized ham radio use world-wide (with a few
countries excluding themselves) starting on 1Jan2013.  True that the
FCC has not yet put into affect rules to allow it in the USA.  I
think it will happen in 2013!

Its risky business to build radios for QRP but Elecraft did.  The KX3
is a risk until several hundred orders came in!
IBM did not take a risk so in 1977 a couple teenagers in their garage
built the Apple and now the only things we read about are i-phones,
i-pods, i-pads...and where is i-bm?

Detroit did not take a risk so in the 1970 gasoline crises several
Asian auto makers captured the small car field throwing GM into a
head-spin downward for a decade trying to catch up.

Typically, if you wait for a market to mature you are left in the
dust of others.  You can be sure there are several innovators looking
at the potential of the new 630m ham band.  Don't worry about
discouraging them!

I think the KX3 still has promise of being a good 630m radio (with a
little help from its friends).  630m will likely be slow to start
(just like the 60m band), but in time there will be a decent
population there.  Right now it is still an experimental band.

Antennas are small for the wavelength but even with 4w ERP my signal
was copied 2893mi distant.  Antenna is about the same size as one for
160m (43x122 foot inverted-L).  Ground-wave propagation to 300-km
appears to be rock-solid (all the time).  My signals were received at
91mi at 35-dB over noise for months with barely a couple dB variation
in strength.  Terrific emcomm potential.  Why the ships used it for
their emergency band when CW was still in use.

73, Ed
-------------------------------
Date: Sun, 08 Jul 2012 15:48:18 -0700
From: Jim Lowman <[hidden email]>
Subject: Re: [Elecraft] K3/KX3 MF/LF Transverter
To: [hidden email]
Message-ID: <[hidden email]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Not to rain on anyone's parade, Bill, but a couple of things
come to mind:

--  I would think it a risky business to develop a transceiver
       for a band that is not yet authorized for amateur use

--   If most of us have trouble getting an antenna going for
        160m - wow - 630m?

Just thinking out loud; not wanting to discourage anyone.

73 de Jim - AD6CW




73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
EME: 50-1.1kw?, 144-1.4kw, 432-QRT, 1296-?, 3400-?
DUBUS Magazine USA Rep [hidden email]
"Kits made by KL7UW" http://www.kl7uw.com/kits.htm
======================================
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: K3/KPA500/KX3 630 meters

KXBill

Ed:
The close in coverage 630m offers, 24/7, is exactly why the interest among our local Emcomm folks.  It will work out extremely well for those in Alaska.
Someone is sure to ask; Will the KPA500  go down that low ?  I imagine with a little tweaking, here and there, it can.


de Bill-w7kxb
. .

> Date: Tue, 10 Jul 2012 00:13:28 -0800
> To: [hidden email]
> From: [hidden email]
> Subject: Re: [Elecraft] K3/KX3 MF/LF Transverter
>
> Jim,
>
> Actually WRC-12 authorized ham radio use world-wide (with a few
> countries excluding themselves) starting on 1Jan2013.  True that the
> FCC has not yet put into affect rules to allow it in the USA.  I
> think it will happen in 2013!
>

     
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: K3/KPA500/KX3 630 meters

Joe Subich, W4TV-4

Sure, I can see the EMCOMM shack on the belt types with their mobile
"high efficiency" 630 meter antennas now!  Anyone calculate the battery
requirements for 5W ERP with even a 16' whip?

200 miles will not even cover Florida from Tallahassee to Miami ...
I can't imagine a use for 630 meters other than as a curiosity.  It
is a shame that ARRL and IARU wasted all of the political capital on
630 meters rather than securing an worldwide exclusive 50 - 100 KHz
wide allocation somewhere useful like 60 meters.

73,

    ... Joe, W4TV



On 7/10/2012 2:37 PM, Bill Harris wrote:

>
> Ed:
> The close in coverage 630m offers, 24/7, is exactly why the interest among our local Emcomm folks.  It will work out extremely well for those in Alaska.
> Someone is sure to ask; Will the KPA500  go down that low ?  I imagine with a little tweaking, here and there, it can.
>
>
> de Bill-w7kxb
> . .
>> Date: Tue, 10 Jul 2012 00:13:28 -0800
>> To: [hidden email]
>> From: [hidden email]
>> Subject: Re: [Elecraft] K3/KX3 MF/LF Transverter
>>
>> Jim,
>>
>> Actually WRC-12 authorized ham radio use world-wide (with a few
>> countries excluding themselves) starting on 1Jan2013.  True that the
>> FCC has not yet put into affect rules to allow it in the USA.  I
>> think it will happen in 2013!
>>
>
>    
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: K3/KX3 MF/LF Transverter

Bill Frantz
In reply to this post by Edward R Cole
As one who has been exploring caves for the last 40+ years, my
principle interest in the 630M band is its ability to
communicate thru solid rock. There is a long history of cave
radios operating on medium frequencies under part 15, most of
which use antennas consisting of a coil of wire. (One of the
rules of thumb for cave radios is that the antenna and the
battery should weigh about the same.)

Cave radios used for communication are quite different from
those used to locate the surface point directly over an
under-ground point, and estimate its depth.

If you are interested in cave radios, most of the work in the US
has been documented in Speleonics, published by the
Communication and Electronics Section of the National
Speleological Society. All issues are available for free
download from
<http://www.caves.org/section/commelect/drupal/speleonics>. The
most recent issue has an index of all issues and is available
from <http://www.caves.org/section/commelect/splncs/splncs28.pdf>.

There is also an active British group, the Cave Radio and
Electronics Group <http://bcra.org.uk/creg/>. They accept Paypal
for their publications.

Cheers - Bill, AE6JV

On 7/10/12 at 1:13, [hidden email] (Edward R. Cole) wrote:

>I think the KX3 still has promise of being a good 630m radio
>(with a little help from its friends).  630m will likely be
>slow to start (just like the 60m band), but in time there will
>be a decent population there.  Right now it is still an
>experimental band.

-----------------------------------------------------------------------
Bill Frantz        | gets() remains as a monument | Periwinkle
(408)356-8506      | to C's continuing support of | 16345
Englewood Ave
www.pwpconsult.com | buffer overruns.             | Los Gatos,
CA 95032

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Loading...