I took a credit course at GW in DC in the mid 80's on "Advances in HF Communications". It included a block on NVIS. It referenced an NRL study done in Viet Nam where NVIS in the 2-10 mHz band was studied. Things like bending a whip nearly horizontal,  dragging a long-wire, or a very low dipole were featured. As I recall that was said to be the "NVIS band" and that D-layer absorption was the negative factor after about 10am local time.  Interesting course.  It might appear that the PRC-47, and its organic NVIS antenna, were products of the study. 
Jeep K3HVG
 
On 08/17/2026 7:44 PM EDT Mike Christie via MRCA <[email protected]> wrote:
 
 
Some may find this interesting when I was in radio school in San Diego in 1968. I was able to listen on low band on our PRC 25s to fire flights going on in Vietnam. After being deployed in Vietnam, Time permitting, I would dial through the PRC 25 and then 77 to see if I could hear San Diego but never did hear anything
Mike…
W1ZFB
 
On Monday, August 17, 2026 at 11:54:03 AM EDT, [email protected] <[email protected]> wrote:
 
Send MRCA mailing list submissions to
    [email protected]
 
To subscribe or unsubscribe via the World Wide Web, visit
    http://mailman.qth.net/mailman/listinfo/mrca
or, via email, send a message with subject or body 'help' to
    [email protected]
 
You can reach the person managing the list at
    [email protected]
 
When replying, please edit your Subject line so it is more specific
than "Re: Contents of MRCA digest..."
 
 
Today's Topics:
 
  1. Re: 2026 Military Radio Collectors Association Meet Sept
      24-26 (Anthony Clare)
  2. Re: Guard 29.4 (B. Smith)
  3. Re: USN/USMC mobile communications (B. Smith)
  4. Re: Attendance at 2026Gilbert (David Ostrander)
 
 
----------------------------------------------------------------------
 
Message: 1
Date: Mon, 17 Aug 2026 07:46:59 -0400
From: "Anthony Clare" <[email protected]>
To: Radio Station KW1I <[email protected]>, "MRCA"
    <[email protected]>
Subject: Re: [MRCA] 2026 Military Radio Collectors Association Meet
    Sept    24-26
Message-ID:
    <[email protected]>
Content-Type: text/plain; charset="us-ascii"
 
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------------------------------
 
Message: 2
Date: Mon, 17 Aug 2026 10:11:30 -0400
From: "B. Smith" <[email protected]>
To: comcast <[email protected]>, Tim <[email protected]>
Cc: [email protected]
Subject: Re: [MRCA] Guard 29.4
Message-ID: <[email protected]>
Content-Type: text/plain; charset=UTF-8; format=flowed
 
It just pops in and out here in Chickenland.
 
Z
 
On 8/17/2026 5:28 AM, comcast wrote:
> vhf low band skip ?- my employer, Atlantic City Electric in New
> Jersey, ?before switching to a Motorola trunked system in the 1990s ,
> had a 4 freq no PL 48 mhz radio system. ?The building I was in had a
> 90 ft pole with a ground plane antenna. Throughout the 80s in the
> summer we would hear skip from the utility companies in the south and
> also southetn California every day loud and clear and cover up our
> mobile 60 watt mitreks. ?Jeff N2IA
> Sent from my iPhone
>
>> On Aug 16, 2026, at 1:34?PM, Tim via MRCA <[email protected]> wrote:
>>
>> ?
>> N6CC is on-freq from CA...
>> Tim
>>
>> On Sun, Aug 16, 2026 at 10:21?AM B. Smith via MRCA
>> <[email protected]> wrote:
>>
>>    Monitor 29.4, the band has been popping in and out.
>>    Z
>>    <semk4che.gif>
>>
>>    ______________________________________________________________
>>    MRCA mailing list
>>    Home: http://mailman.qth.net/mailman/listinfo/mrca
>>    Help: http://mailman.qth.net/mmfaq.htm
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>>
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>>
>> ______________________________________________________________
>> MRCA mailing list
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>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
 
 
 
------------------------------
 
Message: 3
Date: Mon, 17 Aug 2026 10:13:24 -0400
From: "B. Smith" <[email protected]>
To: [email protected]
Subject: Re: [MRCA] USN/USMC mobile communications
Message-ID: <[email protected]>
Content-Type: text/plain; charset=UTF-8; format=flowed
 
Happiness was landing a a SF field and seeing that little control tower.
Z
 
On 8/16/2026 4:18 PM, Jeep Platt via MRCA wrote:
> Our CAP unit got an MRC-22 trailer setup in maybe 1975. That, and a
> small mobile control tower pop-up trailer.? Everything worked but I do
> not recall we ever deployed them.? After a few years, the radios were
> stripped out and trailers turned in.? Oh well...
> K3HVG
>
> Sent from my Verizon, Samsung Galaxy smartphone
> Get Outlook for Android <https://aka.ms/AAb9ysg>
> ------------------------------------------------------------------------
> *From:* [email protected] <[email protected]> on
> behalf of Nick England via MRCA <[email protected]>
> *Sent:* Saturday, 15 August 2026 13:49:16
> *To:* [email protected] <[email protected]>;
> [email protected] <[email protected]>
> *Subject:* [MRCA] USN/USMC mobile communications
> At the prodding of Rich WA6KNW I have created a page with some info on
> USN/USMC mobile radio communications 1940s-50s.
> FWIW https://www.navy-radio.com/mobile.htm
>
> Nick England K4NYW
> Chapel Hill NC
> www.navy-radio.com <http://www.navy-radio.com>
> ______________________________________________________________
> MRCA mailing list
> Home: http://mailman.qth.net/mailman/listinfo/mrca
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[email protected] <mailto:[email protected]>
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> MRCA mailing list
> Home: http://mailman.qth.net/mailman/listinfo/mrca
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[email protected]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
 
 
 
------------------------------
 
Message: 4
Date: Mon, 17 Aug 2026 15:53:47 +0000 (UTC)
From: David Ostrander <[email protected]>
To: "[email protected]" <[email protected]>
Subject: Re: [MRCA] Attendance at 2026Gilbert
Message-ID: <[email protected]>
Content-Type: text/plain; charset="utf-8"
 
 
The 2026 MRCA Meet at the West End Fairgrounds in Gilbert, PA, Sept 24-26 is a month away.This email is a request for you to let the MRCA planning team know what your intentions are
__X__ Planning to come
____ Planning to participate in the Friday field ops from Howell Bldg
_____Planning to bring a demo or display
_____ Planning to bring radio items to sell? (I have three PE-120 Power Supplies for sale)
_____ Planning to be at the Friday night Howell Bldg cookout
_____Planning to be at the Saturday morning Howell Bldg breakfast
_____Willing to spend an hour Saturday morning for two short presentations and a group picture
Dave
On Monday, August 17, 2026 at 05:31:31 AM EDT, [email protected] <[email protected]> wrote:
 
Send MRCA mailing list submissions to
??? [email protected]
 
To subscribe or unsubscribe via the World Wide Web, visit
??? http://mailman.qth.net/mailman/listinfo/mrca
or, via email, send a message with subject or body 'help' to
??? [email protected]
 
You can reach the person managing the list at
??? [email protected]
 
When replying, please edit your Subject line so it is more specific
than "Re: Contents of MRCA digest..."
 
 
Today's Topics:
 
? 1. Re: USN/USMC mobile communications (Jeep Platt)
? 2. Re: 2026 Military Radio Collectors Association Meet Sept
? ? ? 24-26 (Paul Sokoloff)
? 3. Re: Guard 29.4 (comcast)
 
 
----------------------------------------------------------------------
 
Message: 1
Date: Sun, 16 Aug 2026 20:18:30 +0000
From: Jeep Platt <[email protected]>
To: "[email protected]" <[email protected]>
Subject: Re: [MRCA] USN/USMC mobile communications
Message-ID:
??? <PH7PR84MB1679B8F8F771357E4ACF7B01B9D82@PH7PR84MB1679.NAMPRD84.PROD.OUTLOOK.COM>
???
Content-Type: text/plain; charset="us-ascii"
 
Our CAP unit got an MRC-22 trailer setup in maybe 1975. That, and a small mobile control tower pop-up trailer.? Everything worked but I do not recall we ever deployed them.? After a few years, the radios were stripped out and trailers turned in.? Oh well...
K3HVG
 
Sent from my Verizon, Samsung Galaxy smartphone
Get Outlook for Android<https://aka.ms/AAb9ysg>
________________________________
From: [email protected] <[email protected]> on behalf of Nick England via MRCA <[email protected]>
Sent: Saturday, 15 August 2026 13:49:16
To: [email protected] <[email protected]>; [email protected] <[email protected]>
Subject: [MRCA] USN/USMC mobile communications
 
At the prodding of Rich WA6KNW I have created a page with some info on
USN/USMC mobile radio communications 1940s-50s.
FWIW? https://www.navy-radio.com/mobile.htm
 
Nick England K4NYW
Chapel Hill NC
www.navy-radio.com<http://www.navy-radio.com>
______________________________________________________________
MRCA mailing list
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Help: http://mailman.qth.net/mmfaq.htm
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------------------------------
 
Message: 2
Date: Sun, 16 Aug 2026 21:38:24 -0400 (EDT)
From: Paul Sokoloff <[email protected]>
To: Radio Station KW1I <[email protected]>,??? Radio Station KW1I via
??? MRCA <[email protected]>
Subject: Re: [MRCA] 2026 Military Radio Collectors Association Meet
??? Sept 24-26
Message-ID: <[email protected]>
Content-Type: text/plain; charset="utf-8"
 
 
 
The 2026 MRCA Meet at the West End Fairgrounds in Gilbert, PA, Sept 24-26 is a month away.
 
This email is a request for you to let the MRCA planning team know what your intentions are:
 
 
____X_Planning to come
 
___X__Planning to participate in the Friday field ops from Howell Bldg
 
_____Planning to bring a demo or display
 
___X__Planning to bring radio items to sell
 
__X___Planning to be at the Friday night Howell Bldg cookout
 
__X___Planning to be at the Saturday morning Howell Bldg breakfast
 
__X___Willing to spend an hour Saturday morning for two short presentations and a group picture
 
 
 
Please reply at your earliest.
______________________________________________________________
MRCA mailing list
Home: http://mailman.qth.net/mailman/listinfo/mrca
Help: http://mailman.qth.net/mmfaq.htm
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Message: 3
Date: Mon, 17 Aug 2026 05:28:57 -0400
From: comcast <[email protected]>
To: Tim <[email protected]>
Cc: [email protected]
Subject: Re: [MRCA] Guard 29.4
Message-ID: <[email protected]>
Content-Type: text/plain; charset="us-ascii"
 
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------------------------------
 
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End of MRCA Digest, Vol 268, Issue 23
*************************************
 
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End of MRCA Digest, Vol 268, Issue 24
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