Wednesday, October 12, 2022

History of the 11m HAM band

  We know the 11m or the 27MHz (27-Mc) band as CB (Citizens Band) band. Some people refer to it as the "chicken" band. CB radio was very populair before everyone had a mobile phone and internet. When you search for the 11m band history you will read numerous sites about how 11m CB started in 1958 with highlights in the seventies of last century including movies like "Smokey and the bandit", "Convoy" and "Handle with care". But not many know that the 11m was a legal HAM band at least in north/south america, australia, new zealand, south africa and south-west africa from 1947-1958. 

Following several publications first experimental license was given to W6XBC (eXperimental BroadCast) in 1933, the experimental frequency was 27,1 MHz. Actually 27 MHz was considered VHF at that time. Transmissions took place from Yuma, AZ. The aim was to see if VHF was useful for remote broadcast pickups. They transmitted 1 hour per week and asked for reports. At around the same time the same frequency was used by a ship that was on arctic expedition. They used several callsigns, one of them was W10XDA.

But searching for more historical research I found that first commercial licenses were given in March 1928 to 6XAR in San Fransisco CA transmitting on 27,523 MHz, 2XBM in Water Mill NY transmitting on 27,900 MHz and 6XJ in San Diego CA transmitting on 27,900 MHz.

In the WW2 years 27MHz communication gear was used in tanks both by Germans and American armed forces. A story that can be read in several old CB magazines is about discovering 27MHz signals heard from German tanks stationed in Africa. Fiction or real, a HAM from Rhode Island recorded some strange voices he heard on the 11m band. One day he played the recording to a friend who understood German. This friend realized it was some military communictian between tanks and base stations. When the US Navy was called in they found out it were tanks from general Rommel in North-Africa. Although the signals came in almost everyday it seems best to receive was at a few square miles in the Rhode Island territory. Intelligence immidiatly took over an old farmhouse at the sweet spot en installed a few 11m receivers and German translators. Every information that was transmitted in North-Africa by the German tanks and base stations was monitored and given to the British. After the war the 27MHz was no longer in use in the military but it certainly proves that this frequency did do well in difficult circumstances.

Other users of 27MHz were doctors that used this frequency for medical uses like diathermy. This, of course, was a huge source of QRM and so the 11m was not really a populair HAM band. In 1947 the FCC allows use of the 11 meter band on a shared basis with Industrial, Scientific and Medical devices. Most HAMs operate on 11m with their 10m antenna, not really effective. In 1948 Firestone Tire Company granted experimental license W10XXD for 27.255 MHz (Ch 23) using two 3Watt transmitters. All documentation about this experiment is lost but these might be forerunners of CB radios as we know it now. 

Did you know that the US radio technical planning board proposed to lower the 10m amateur band by 1 MHz to 27-29 MHz. Although this proposal was later withdrawn, the ISM band (27,185 - 27,455 MHz) was not established until 1945, and the FCC hinted that it could be distributed to amateurs as a secondary service.

The 11m HAM band has been changed several times:

27.185-27.455MHz (March 26, 1946 to April 29, 1947) FCC Order 130-D (March 13, 1946), Federal Register Notification (11FR3158, March 26, 1946)

27.160-27.430MHz (April 30, 1947 to June 30, 1949): FCC Order 130-M (April 10, 1947), Federal Register Notice (12FR2815, April 30, 1947)

26.960-27.230 MHz (from 1 July 1949 to 10 September 1958)

The 11m HAM band was not only established in the USA. It seems 11m was also allowed in the America's (Canada, central/south America), South Africa, Southwest Africa, Australia and New Zealand.  International DX contacts were certainly possible.

But what did the HAMs do on 11m? Did they use it for nearby contacting or did they do make some DX? I searched in some old magazines to find evidence and found some remarkable things. Activity without the need for a experimental license was from 1947-1958.

-  1947 - The mountaineer amateur radio association operated W8BOK/8 at fieldday with 6 stations simultaneously. One of the stations operated "27-Mc phone".

- W3CDQ is planning a 27-Mc. 'phone-cw rig for a net composed of amateurs connected with the Central Radio Propagation Lab. (CRPL) ionosphere group.

- Several amateurradio stations researched meteorscatter on 27-Mc

- 1948 - QST June 1948 reports W9AND,  worked EL5A, OX3GE, VO4T, KH6GT, KII6BI and CXlFB. W6ZZ reports working J9AAI. All on 27-Mc.

- 1950 - The 16th ARRL International competition also counts (DX) contacts on 27-Mc.

- 1957 - The FCC announces the end of the 11m HAM band to use it for "Citizens Band"
"Save 11 meter" contests were hurriedly organized among the Hams to show the FCC that 
there really was life in the old 11 meter band. About 400 stations rose to the occasion, and 
many exotic calls were to be heard, such as CX2AY, CN8JW, XE1A, ZP5IB, VK2QL, and 
KC4AI. Unfortunately these "protests" are not enough and didn't help to convince the FCC. 

The 11m HAM band came to an end. September 11 1958 was the date that 11m would be known as "Citizens Band". In fact Al Gross W8PAL is by most seen as the man that invented CB, although the idea was already brought up in 1938 by Herbert Brooks W9SDG. His letter to the editor of QST magazine described a theoretical "Citizens Band" nearly identical to what we know today. Al Gross actually developed equipment for the UHF band since CB on an experimental basis at that time was on 250MHz and later between 460-470MHz. It looks like he had the first official CB license issued in 1948. But W2XQD was really the first one with a CB license issued February 14, 1947. It would actually take another decade before CB started on the 11m band. 



Related reading links and documentation:

Detailed information about the schooner Morrissey arctic expedition radio experiment:

https://www.rsp-italy.it/Electronics/Magazines/QST/_contents/QST%201934_12.pdf

History of the 11m band documentation:

https://ukspec.tripod.com/rf/cb/

https://www.retrocom.com/wtcollect/27_megacycle_history_in_the_u.htm

https://sites.google.com/site/cb465mhz/home

Another article I wrote about Al Gross:

https://pe4bas.blogspot.com/2014/11/historical-first-time-1944-handheld.html

6 comments:

VE9KK said...

Good morning Bas, very interesting reading and I was shocked to read how as I know it "CB radio" was so much more. When I was in my teens it was CB radio that got me hooked and exploring and I found myself later in life as a ham.
73,
Mike
VE9KK

Bas PE4BAS said...

Many HAMs have been on CB in their younger years. I've been on CB since 1979 and still am. Though I have to divide my time of course. I'm primairely on the HAM bands but like to talk to some old and new friends on CB. 73, Bas

PA2RF said...

Same here, started with CB radio in 1978. Remember frequency of channel 14 by heart; 27.125 MHz 73 Ron PA2RF

Richard KW0U said...

The reception of 11 meter Afrika Korps tank communications in Rhode Island reminded me of a similar situation in 1951. Then, U.S. tanks in the Korea War picked up 10 meter ham operations from the U.S. When informed about this hams stayed off these frequencies until the army changed its own wavelengths. Sometimes history does repeat. (Reference: "50 Years of A.R.R.L.", p. 123)

MadDogMcQ said...

Blimey, I had no idea there was so much history to “plain old” CB - that’s amazing! Like most people, I just thought it came about in the 70’s. To be totally honest, I didn’t care for it too much because there were so many “muppets” as we called them back then, who just constantly messed around. I only stayed with it a couple of years.

I recently monitored the UK FM channels and found that it hadn’t improved much, well certainly not around here LOL.

Hope you’re well.

73, Tom, M7MCQ.
www.m7mcq.com

PE4BAS, Bas said...

@KW0U tnx for the comment Richard. Didn't know about that, nice info. Although not 11m.

@M7MCQ Tom, tnx for the comment. Many only know the "muppets" on the CB "chicken" band. I refer to the superbowl on ch.6 for instance. I've been there, I listened to it and didn't like it. My interest was 11m DX. Worked/confirmed over 250DXCC on 11m long time ago. The 11m DX community is just as serious as on the HAM bands. It is a very tight group with not much info since the part of the 11m they use is illigal in most countries. I wish I could write more about it but it is not wise to do that. I know of some 11m DX enthousiasts that have over 300 DXCC confirmed on 27MHz. Considering that in some countries there is a death penalty is you are caught it is a remarkable accomplishment. It is a well hidden secret that sometimes HAMradio DXpeditions also appear on 11m. I hope that somewere in the future the 11m will be openened and not be illigal anymore. Actually I anticipated it would happen years ago, but time is not yet ready for it. 73, Bas