From nntp04.primenet.com!nntp.primenet.com!howland.erols.net!cam-news-hub1.bbnplanet.com!cpk-news-feed2.bbnplanet.com!cpk-news-hub1.bbnplanet.com!newsfeed.internetmci.com!news.comm.net!not-for-mail Mon Sep 2 15:10:14 PDT 1996 Article: 1858 of alt.conspiracy.jfk.moderated Path: netcom.com!nntp04.primenet.com!nntp.primenet.com!howland.erols.net!cam-news-hub1.bbnplanet.com!cpk-news-feed2.bbnplanet.com!cpk-news-hub1.bbnplanet.com!newsfeed.internetmci.com!news.comm.net!not-for-mail From: Greg Jaynes Newsgroups: alt.conspiracy.jfk.moderated Subject: REPOST: Dallas PD radio Date: 26 Aug 1996 20:14:42 -0500 Organization: Flashnet Communications Lines: 304 Sender: jmcadams@able.comm.net Approved: lho@earthlink.net Message-ID: References: <320CAE15.23D2@execpc.com> NNTP-Posting-Host: able.comm.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 2.01KIT (Win95; U) Status: OR David Humphreys wrote: > > Hey all, this newsgroup seems a lot better than > alt.conspiracy.jfk. Oh well, here's my question: > > I've heard that at the time of the JFK assassination, somebody > either on the Dallas Police Dept. or somebody with a programmable radio > (I don't know if these were availible in 1963) set to the Dallas Police > Dept. radio frequency was holding an open mike. This was for the > duration of the assassination and for a long time afterwards. > Due to the radio technology in 1963, holding an open mike and > not transmitting (just pushing down and holding the "transmit" button) > meant that NO ONE ELSE could broadcast on that frequency. So the Dallas > PD could not respond quickly to the shooting. > Has anyone else heard of this? I heard it from a Wisconsin > State Patrol officer who was alive in 1963 (I wasn't). Thanx in > advance. > > shaggy@execpc.com At the time of the assassination, the Dallas Police were operating two radio channels which were both being recorded at headquarters. Channel one was being recorded onto a Dictabelt machine. A dictabelt is a plastic sleeve that fits around a platen in the machine. As the platen rotates a needle assembly records the radio frequency by cutting a groove into the sleeve just like on a turntable record . It can be played back in the same manner. Channel two was being recorded onto a Gray Audograph machine. An Audograph record looks similar to regular LP record Album. Acoustics experts commissioned by the House Assassinations Committee determined that certain impulses on a portion of the channel one dictablet recording could have been the effects of rifle fire. The experts could demonstrate the waveform of the impulses with spectrographic charts. But the human ear can not distinguish gun shots from the overwhelming background noise on the recording. The official opinion is that Dallas Police Officer H.B. McLain who was riding a motorcycle in the motorcade had a microphone that was stuck in the "ON" position during the assassination and after. This is a conclusion of the HSCA. In Robert Groden's documentary "The Case for Conspiracy", he cites a point in a DCA * film when McLain reached down on the lower left area of his motorcycle and adjusted the microphone in some way. Groden say's this was the when the jamming of police channel one began. McLain told me that his microphone switch was on the handlebar of his motorcycle. He also said that it was not his microphone that was stuck on. He said that if his microphone was the one that was stuck on then the channel one recording would contain the sound of his police siren from the point he engaged his siren all the way to Parkland Hospital. McLain said he had stopped his motorcycle on Houston street when the cars ahead in the motorcade stopped. He said he was in a position to see thru the ornamental squares in the white wall across from the reflecting pool that separates the Houston street portion of the monument from the infield grass. The grass is situated between Elm and Main streets. He said he could see Jackie on the trunk of the car thru one of the square openings. McLain said he was stopped there until he heard Dallas Police Chief Curry give the order "Go to the hospital..." . He said he then kicked on his siren (a foot activated device that connected a friction wheel to the front tire of the motorcycle) and sped around traffic on Houston and Elm streets. He entered the ramp to Stemmons frwy and approaching speeds of 100mph caught the presidential limo beyond the Continental street exit which is about a half mile from the plaza. He then assisted in the police code 3 escort to Parkland Hospital. The interesting thing here is that Chief Curry broadcast the "Go to the hospital..." message on police channel two. If McLain's radio was jamming channel one, how could he hear a message on channel two? When the microphone is keyed, the receiver stops. Researcher Gary Mack explains that McLain could have heard another police motorcycle radio that was near him and tuned to channel two. This may be, but we don't hear the "Go to the hospital" on channel one. If the transmission of another motorcycle was near enough for McLain to hear, then his supposed stuck microphone should have picked it up and transmitted it onto channel one as crosstalk. Remember the microphone is suppose to be able to record the sound of gunshots that the human ear can not hear on the tape. Why should McLain's human ear be able to hear a channel two broadcast that the microphone cannot pickup? THE DALLAS POLICE In case you would like to ask them anything, here are their phone numbers. Be prepared for varying degrees of cooperation: (Dallas Police information (214) 670 - 3011 ) (Dallas Police Motorcycle Division (214) 670 - 6954, radio shop (214) 670 - 8755) BACK TO THE SIRENS On the dictabelt recording of channel one, the sirens cannot be heard until two minutes after the supposed shots were fired and recorded in Dealey Plaza. Then what you hear is the "Doppler effect", you hear the sirens coming toward you then going away. The sirens sound on the tape lasts 36 seconds. If McLain's microphone had been the one stuck, the siren sounds should be constant. HSCA Despite this, the HSCA let themselves get trapped in a circular argument by Dr. Mark Weiss. Dr. Weiss was hired by the committee to double check and expand on the work of their other acoustics experts from the firm of Bolt, Beranek and Newman Inc. who had determined that there was at least four impulses on the tape that could not be ruled out as rifle shots. And that there was a fifty percent chance that one of the impulses originated from the grassy knoll. Specifically, if you marked all the impulses on a timeline from earliest to latest, the third impulse is the one thought to have originated from the "grassy knoll". Dr. Weiss and his assistant examined the data collected by BBN . After performing additional calculations they determined that there was a ninety five percent chance of a rifle shot from the grassy knoll. Their conclusions about the acoustical data were based on the supposition that H.B. McLain's microphone was the one that was stuck "ON" and recorded the shots/impulses. Dr. James Barger was the chief scientist for BBN. PORTION OF DR. JAMES BARGER TESTIMONY TO THE HSCA Mr. FITHIAN. While they are doing that, let me ask you sort of the central question. Is it your conclusion that you proved that there were four shots? Dr. BARGER. No. (......read that part one more time.......-GJ) Mr. FITHIAN. With regard to the groupings of shots what do you prove then? Dr. BARGER. As regards the grouping of the shots, we demonstrated with high confidence that *if * there are four shots, we demonstrated the times at which they occurred, and the intervals between them were described by Mr. Cornwell, 1.6 seconds, was it 5.9, and 0.5. Mr. FITHIAN. Would you repeat that again, please? Dr. BARGER. Yes. Mr. FITHIAN. The distance, the time frame between the first and the second shot is what? Dr. BARGER. 1.6 seconds. Mr. FITHIAN. And between the second and what you perceived to be a possible third shot? Dr. BARGER. 5.9. Mr. FITHIAN. And between the possible third and the possible fourth shot? Dr. BARGER. 0.5. Mr. FITHIAN. 0.5? Dr. BARGER. 0.5, one-half second. Mr. FITHIAN. One-half second. So what you are saying, Doctor, is that if there were four shots fired, they came at those intervals? Dr. BARGER. Yes. END OF BARGER TESTIMONY PORTION OF DR. MARK WEISS TESTIMONY TO THE HSCA Mr. CORNWELL. In addition to the tests that Dr. Barger conducted, did you need anything else, any other information in order to follow this process? Mr. WEISS. Well, yes. We needed, in order to perform this prediction process, we needed to know a number of things. First, we needed to know where the sources of sound were. Now, of course, that means we had to have some idea of where a shooter might have been, and by all indications, he had to be someplace up on the grassy knoll, and we had that area taken care of. We had to know, of course, also where the reflecting surfaces were. That is for a particular assumed position of the microphone, where the major reflecting surfaces were. So we had to refine our understanding of how the echoes were produced in that case. We had to know approximately where the motorcycle was, because although this technique is simple and straightforward, it can become pretty tedious if you don't know approximately where or reasonably well where the motorcycle is, and you can assume it to be anywhere in the Plaza. So we had to have some idea where it was. And what we assumed was that it was approximately in the neighborhood of that microphone that gave the strongest matching pattern in Dr. Barger's experiment between a shot from the knoll and the impulses audible on the police tape recordings. Furthermore, in order to calculate the echo times, the time of arrival at each of these echoes, we had to know what the velocity of sound was in the air. As I said before, the velocity of sound is constant in all directions. However, it is not always the same value. In particular, it is a function of the temperature of the air. So we had to find out what was the temperature of the air at the time of the assassination. And that was about all we really had to know in order to perform the prediction. END OF WEISS TESTIMONY Based on the acoustical evidence, the HSCA concluded there was probably a conspiracy to assassinate President Kennedy. CROSSTALK Steve Barber is credited in many books about the assassination as the "rock drummer" who heard the crosstalk which led to the National Academy of Sciences rebuttal of the conclusions of the HSCA. This is not fair to Steve. Although he has no problem with it, I prefer to refer to Steve as an outstanding and knowledgeable researcher who happens to play a mean set of drums. Gallery Magazine released an issue that contained a paper 45 RPM recording of the Dallas Police channel one stuck microphone sequence which was narrated by researcher Gary Mack. Steve bought the issue and "rocked" the HSCA. The human ear simply cannot hear any gunshots on the record at the point the HSCA claims they occurred. Still Steve listened attentively trying to hear them . He knew the point on the record when the shots were to have occurred because you can time from the point a voice makes the statement "allright Chaney". While Steve was listening attentively, he heard something that no one else had heard. He heard a barely audible transmission. He heard a voice say "Hold everything secure...until Homicide and other investigators can get there........" Steve couldn't believe it. The voice he heard was that of Dallas Sheriff Bill Decker. Steve recognized the "Hold everything secure....." statement as a transmission that Sheriff Decker had made on police channel two. Decker made this statement at a point in time known to be well after the shooting. Now the question was "How come Sheriff Decker's voice is being recorded saying this at the instant the shooting is to have occurred? The explanation was that the acoustics experts picked the wrong point on the tape and incorrectly defined some impulses as gunshots. Decker's voice was being recorded as crosstalk. In other words, two police motorcycles were situated close to each other. One motorcycle microphone was stuck "ON" and recorded everything in it's immediate surroundings onto channel one. The other motorcycle had it's radio on police channel two and when Decker made the "Hold everything....." statement, it was broadcast onto channel one by the microphone that was stuck on. Crosstalk. As a result of Steve Barber pointing out this Decker crosstalk, the National Academy of Sciences Committee on Ballistic Acoustics reinvestigated the procedures of BBN and Dr. Weiss. The committee found problems in the "certainty" that the stuck microphone actually detected the sound of gunfire. They also determined that the evidence did not support a conclusion of a 95% probability that a shot came from the grassy knoll. The technical aspects can become overwhelming. But this much seems to be true. 1.) There was a microphone stuck on somewhere in Dallas at the time of the assassination. 2.) The microphone did record the sound of sirens. Probably the sound of JFK's limo and the motorcycle escorts. When you consider the "Doppler Effect" mentioned earlier, it would seem that the stuck microphone would have to be somewhere *between* Dealey Plaza and Parkland Hospital. Because of the timing that the sirens are heard, we can make some rational assumptions in a general way, where the microphone would have to be, if it were in fact somewhere between Dealey Plaza and Parkland Hospital. Current Dallas Sheriff Bowles who was the sergeant in charge of the radio recordings at the time of the assassination believes that a motorcycle at the Dallas Trade Mart had the stuck microphone. Since the sound of sirens on the recording produced a "Doppler Effect", this would make sense. We know the limo and motorcycles with sirens wailing approached, then passed the Trade Mart. H.B. McLain told me that he and Sheriff Bowles determined that Dallas Police Officer Leslie Beilharz who rode a three wheel motorcycle was who had the stuck microphone. Beilharz was assigned to the area around the Trade Mart. The reason McLain thinks Beilharz had the stuck microphone was because of his habit of whistling. At one point on the stuck microphone sequence you can hear someone whistle. * Dallas Cinema Associates Sources: Discussions with Gary Mack, Steve Barber, Robert Groden and H.B. McLain, report of the HSCA vols 2 & 5 and the National Research Council's Report of the Committee on Ballistic Acoustics. Greg Jaynes