Suppression of ideas

I found this video called Empire of Noise about broadcast radio jamming. It seems to be about ten years old and is a post-cold War documentary about the jamming of radio signals by the USSR, Warsaw Pact counties, and China.  It is an interesting look into the extent and expense that governments will go to suppress counter thoughts and ideas.

The video is quite long, and there are stretches of jamming noise that can be annoying, but perhaps that is the point.  It is worth the time if interested in history and radio broadcasting.  You know what they say about history; those that do not understand history are destined to repeat it.

A few of the highlights:

  • The former Soviet Union had the most extensive jamming network of anyone on Earth.  There were groundwave jamming centers in eighty-one Soviet cities which consisted of approximately 10-15 transmitters each in the 5 KW covering the medium and shortwave frequencies.
  • Each groundwave jamming station consisted of a transmitter site and a receiver/control site.  The receiver site possessed lists of frequencies to monitor, when objectionable material was heard, the jamming transmitters were turned on.
  • There was a skywave jamming network consisting of 13 jamming stations with 10 or more 100-200 KW transmitters in each.  There were some transmitters in the 1,000 KW power range.  These were located in Krasnodar, Lvov, Nikolaev, Yerevan, Alma-Ata, Grigoriopol, Sovieck, Novosibrisk, Tashkent, Khanbarovsk, Servdlosk and Moscow (some of these names may have changed).  These operated in a similar fashion to the groundwave jammers.
  • After the sign-off of government stations, Soviet jammers sent a blanketing signal on the IF frequency (most likely 455 KHz) of receivers to effectively block them from receiving any station while USSR government stations were off the air.
  • Baltic states had 11 jamming stations with approximately 140 transmitters
  • Ukraine had approximately 300 Jamming transmitters.
  • Warsaw Pact countries had extensive medium-frequency jamming networks.
  • It is estimated it takes about 20 times the transmitted power to jam any one signal.

The entire jamming network was hugely expensive to equip and operate, costing several tens of millions of dollars per year.

It is interesting that the US position in all of this was:

Everyone has the right to seek, receive and impart information through any media and regardless of frontiers.   Jamming of radio broadcasts is condemned as the denial of the right of persons to be fully informed concerning news, opinions and ideas.

Sounds perfectly reasonable.  The free exchange of ideas and information over the internet is something that should be guarded carefully and should not be restricted or censored.  Perhaps somebody should inform Congress.

WBCN All digital field test results

When I said the WBCN test data may not see the light of day, perhaps I spoke too soon.  For your viewing pleasure, here are the results of the WBCN all-digital HD Radio tests:

WBCN All-digital AM IBOC Field Test Project (link has been broken, this may have been released by accident)

Well, that will teach me, won’t it.

I have given it a summary read and my first impressions were correct; from a technical standpoint (antenna, ATU)  this is a very favorable test configuration.  The results look pretty good on the surface, although they appear to have had some nighttime interference problems, go figure.  I’ll update this post when I have time to fully read the whole paper.

Update: The link I provided earlier has been taken down.  It may be that the information was not supposed to be released to the general public.  Several people have asked me to upload the report to my own server so that they can download it and read it themselves.  This leaves me in a bit of a quandary; the report itself is important information and its implications for the future of broadcasting are huge.  On the other hand, it is the work of a private organization and not the public domain, thus if released by accident, then it should not be shared.

This story from Inside Radio is more or less accurate as to what the report contains, although it paints a somewhat favorable picture.  There appear to be some issues meeting the NRSC5C mask for the MA3 (all digital) mode.  That seems to be fine, however, as the NRSC5C mask can be modified to meet field conditions.  How convenient is that?  The information about the number of AM HD Radio stations seems a bit off, latest I have is 207 AM daytime, and 66 AM nighttime stations out of 4,659 transmitting hybrid digital-analog HD Radio, or 4% daytime and 1% nighttime respectively.

When I have time, I will do some more analysis and post my own conclusions.

As requested: The old WSBS studio building

Alan asked if I should ever find a picture of the old WSBS studio building to publish it.  Here it is:

WSBS old studio building
WSBS old studio building

I found this above the coffee machine in the lobby, nicely matted and framed.  I didn’t want to ruin the framing job, so I took a picture of the picture under glass and cropped it, so thus the quality could be better.

I believe this is the original tower from 1959.  The current tower stands on a taller concrete pedestal and is further away from the road.  I think the roadway was widened and raised at some point, thus the new building sits higher in relation to the tower base.  In any case, it little bit of radio history.

Moving and upgrading a translator

Something that I eluded to in a previous post, we finalized the move of the WSBS translator, W231AK, from the Fairview Hospital in Great Barrington to the side of the AM tower.

Tower crew hanging translator antenna on AM tower
Tower crew hanging translator antenna on AM tower

The move was started by hanging a new Shively 6812B antenna from the side of the AM tower, located off of US 7, north of Great Barrington. This is a half-wave-spaced circularly polarized antenna.

While this work was going on, some guy from OSHA showed up and started taking pictures without asking permission or telling anyone who he was.  We informed him that he was on private property and asked him his reasons for being there.  He got in his car and left, no doubt to a parking lot down the road so he could keep the tower climbers safe… mostly from themselves… by levying huge fines for free climbing…  Wasn’t there something in the news about the government running out of money?  Anyway…

W231AK antenna, Great Barrington, MA
W231AK antenna, Great Barrington, MA

WSBS had been using this translator for a few years. The advantages for the station from the translator move are greater power output (from 35 watts to 250 watts ERP) and less operating expenses in the form of TELCO line charges and roof top rental at the Hospital.

WSBS tower with W231AK antenna mounted
WSBS tower with W231AK antenna mounted

In addition to that, the reliability of the translator should increase, as there have been several instances in the past when TELCO line problems have taken the translator off the air for days at a time.

W231AK new transmitter
W231AK new transmitter, WSBS base current meter below

The transmitter for W231AK was changed from a Crown 35 watt unit to a BW Broadcast T600.  These units are made in the UK and it is an all-in-one processor/exciter/transmitter. We took the cover off to make a few configuration changes and the entire unit is very well made.

BW Broadcast T600 insides
BW Broadcast T600 insides

One of the nice features of this particular transmitter is the screw-down clamping method of connecting the RF devices. Lets face it, unsoldering MOSFETS is a PITA. This screw down clamp eliminates all that.

BW Broadcast T600 power amp
BW Broadcast T600 power amp

The audio input and processing board is pretty neat too.

BW Broadcast T600 audio input board
BW Broadcast T600 audio input board

There are several different processing settings which we played around with.  All in all, it seems like a pretty solid unit and I would recommend it to anyone looking for a low to moderate power transmitter.