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Non-techie asks for help................
Hi folks, first let me apologise for not lurking, or even reading a
FAQ (I did look and did not find). I know that radio amateurs are a helpful and friendly bunch, so here goes. From the UK, for historical reasons, the BBC broadcasts programmes on Long wave, specifically 1500 metres (198 Khz???). I drive a truck on the continent of Europe, and would love to listen to this service whilst on the road (for the cricket!). I know that the signal is there, and of sufficient strength, as I can receive it OUTSIDE the truck on an ancient "portable" Inside the steel box (cab) however, too much noise/too little signal to be useful. The fitted radio has LW, but again cannot be used for the noise. Could anyone please point me to some answers to the following: Antennae: Could I build (buy) some kind of antenna specifically to receive this emission? (My old radio has a socket labelled "AM antenna"). Could I build a receiver tuned only to this freq., with no need for a speaker (run the sound in at headphone type power) that I could hang/bolt outside the truck (on the roof?), with its own battery and aerial? If so could someone point me to a diagram of such a beastie? |
Stephen Parry wrote:
Inside the steel box (cab) however, too much noise/too little signal to be useful. Is the noise coming out of the radio speaker or is it the physical noise level that is the problem? -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Stephen Parry wrote:
"I drive a truck on the continent of Europe, and would love to listen to this service on the road for cricket." The Blau Punkt in my Karman Ghia got such signals all over the continent, and I`m just one of millions. Mr Parry did not say if his truck is Diesel powered as most European trucks are. If so, he is free of his own ignition noise, usually the hardest to suppress. He still may have alternator whine (perhaps a bad diode) and he may have static discharges from things which rotate. Some are under the hood, and their radiation should be kept under the hood by the metal surrounding them. All such metal pieces should be bonded together to keep the trap they form closed. All conductors coming through or under the firewall should be well grounded or bypassed with capacitors at the firewall. The exhausr pipe may need bonding here also. Maybe there is a gasoline powered rerfrigeration compressor generating ignition noise. Standard resistance wires, capacitors, and bondibg should silence that. Springs can be used in wheel hubs to ground out static. All the metal parts of the truck may have to be bonded together. My Blau Punkt was equipped with a good sized choke coil in its battery lead. It also had an internal "spark-plate" capacitor, and these rid the power source of radio noise. The telescoping antenna (about 50 years ago) could be extended to about 100 inches, which made the Karman Ghia quite a sight, but it worked. The antenna cable was the standard high-impedance small inner-wire coaxial type. This must be intact and perfect to keep the signal on track and the noise out. Though German, it used Motorola connectors. Radio frequencies decline very rapidly near their source. This is your friend when the source causes interference. Keep the antenna away from and shielded from sources of interferebce. In 1935, Alfred A, Ghirardi (E.E.) wrote: "---an aerial must be installed in (or on) the roof, under the running boards or chassis of the car, or in some other locations. ---Considerable attention must be given to the ignition and other electrical wiring of the car in order to eliminate all electrical interference which it produces in the receiver." Noise problems are more often caused by the vehicle than by the receiver but some receivers may not be shielded and filtered well enough. If the truck cab has its pieces bonded together and all pass-through conductors are well bonded or bypassed, it should be electrically quiet. You should be able to use a portable radio in there with proper placement or an outside antenna. Ghirardi devotes an entire chapter to automobile radio installation in "Modern Radio Servicing". Car radios are hot in the summer months while home radios are not. Best regards, Richard Harrison, KB5WZI |
One problem you might look at aside from all the other great suggestions is
to look at how your radio voltage is derived. Most trucks are 24 volt and the radios 12 volt. Are you tapping at the junction of the two twelve volt batteries or does your truck use a 24 to 12 volt converter? These are usually really noisy from an electrical standpoint. "Stephen Parry" wrote in message ... Hi folks, first let me apologise for not lurking, or even reading a FAQ (I did look and did not find). I know that radio amateurs are a helpful and friendly bunch, so here goes. From the UK, for historical reasons, the BBC broadcasts programmes on Long wave, specifically 1500 metres (198 Khz???). I drive a truck on the continent of Europe, and would love to listen to this service whilst on the road (for the cricket!). I know that the signal is there, and of sufficient strength, as I can receive it OUTSIDE the truck on an ancient "portable" Inside the steel box (cab) however, too much noise/too little signal to be useful. The fitted radio has LW, but again cannot be used for the noise. Could anyone please point me to some answers to the following: Antennae: Could I build (buy) some kind of antenna specifically to receive this emission? (My old radio has a socket labelled "AM antenna"). Could I build a receiver tuned only to this freq., with no need for a speaker (run the sound in at headphone type power) that I could hang/bolt outside the truck (on the roof?), with its own battery and aerial? If so could someone point me to a diagram of such a beastie? |
Richard, can one drive far enough in Europe that the drive time would allow
listening to an entire cricket match? I mean here in the states it might be possibe, say from New York to Texas etc... "Richard Harrison" wrote in message ... Stephen Parry wrote: "I drive a truck on the continent of Europe, and would love to listen to this service on the road for cricket." |
As most modern big trucks are fiberglass, the bonding is moot.
"Richard Harrison" wrote in message ... are under the hood, and their radiation should be kept under the hood by the metal surrounding them. All such metal pieces should be bonded together to keep the trap they form closed. All conductors coming through or under the firewall should be well grounded or bypassed with capacitors at the firewall. The exhausr pipe |
Fred, W4JLE raised a number of intresting points. DC to DC converters
are switching types to get high efficiency and this can generate many harmonics. If not suppressed, as many converters are, this causes much noise. The solution is to use the proper converter if required. Yes England can be well received all over the European continent. The transmissions are powerful and decline only about 6 dB every time distance from the transmitter is doubled after the first 1.5 km from the 200 KHz transmitter. The questioner referred to his truck cab as a "steel box". I accept his word. However, I once had a Corvette with a fiberglass body. The ignition system came well shielded and bypassed. The underside of the hood was equipped with a fibergaass blanket for heat control and the blanket was faced with aluminum foil for radio frequency control. It was grounded. Trucks must use something similar if they have spark ignition systems. The Corvette`s Delco radio only had medium wave AM and VHF FM reception. Both were satisfactorily quiet. Screams during acceleration and sudden stops were the only disconcerting noises. Best regatrds, Richard Harrison, KB5WZI |
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Walter, W2DU wrote:
"Did you have a large inheritance?" No big windfall. I worked in Europe on a good salery for years. After the first two, all I had to do was stay away rrom the U.S.A. and my salery was tax-free. Then I investerd for the long term in some unspectacular stocks with rising earmimgs and stock ptices. For fun I bought some hot short term stocks too. I won some and I lost some, but you only have to make one killing to pay for the losses. Diversification is the key to staying in the game. Timing the market is highly unlikely. So is reliable information unless it is first-hand. I could tell you that Motorola is cash-rich and is buying back anout 10% of its stock, but the Galvins are gone (except for Christopher) so the stock is questionable. The management must think the stock is a good investment or they shouldn`t be buying it. Who knows? Best regards, Richard Harrison, KB5WZI |
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Richard:
You should be advised that modern semiconductor driven diesel injectors are noisier than Kettering ignition systems. DIN and the rest of the European regulatory bunch have really clamped down on spark fired ignition noise, but apparently Diesels have escaped their attention. -- Crazy George The attglobal.net address is a SPAM trap. Please change that part to: attdotbiz properly formatted. "Richard Harrison" wrote in message ... Fred, W4JLE raised a number of intresting points. DC to DC converters are switching types to get high efficiency and this can generate many harmonics. If not suppressed, as many converters are, this causes much noise. The solution is to use the proper converter if required. Yes England can be well received all over the European continent. The transmissions are powerful and decline only about 6 dB every time distance from the transmitter is doubled after the first 1.5 km from the 200 KHz transmitter. The questioner referred to his truck cab as a "steel box". I accept his word. However, I once had a Corvette with a fiberglass body. The ignition system came well shielded and bypassed. The underside of the hood was equipped with a fibergaass blanket for heat control and the blanket was faced with aluminum foil for radio frequency control. It was grounded. Trucks must use something similar if they have spark ignition systems. The Corvette`s Delco radio only had medium wave AM and VHF FM reception. Both were satisfactorily quiet. Screams during acceleration and sudden stops were the only disconcerting noises. Best regatrds, Richard Harrison, KB5WZI |
The fitted radio, thanks to my skinflint boss is a "bare minimum"
Mercedes branded unit, actually made by Becker, I believe. It is therefore a good quality, if basic, piece of kit. The antenna is I guess from the same "box" ie standard quality etc. FM reception, for instance is OK. All the truck electrics, including the radio are 24V, albeit from 2 X 12V batteries in series. The built in unit is JUST tolerable on AM when there is a really good signal ie in the UK, if the signal is at all weak (I am guessing here), other noise dominates ie a rhythmic low frequency "fart" noise, (I guess this comes from the tachograph, stupidly fitted next to the radio) A whine, related to engine revs (alternator?? fuel pump??) horrible noises whenever I pass under a bridge or anywhere near power pylons or railway lines. The portable radio (with its own batteries 8 X D size = £24.00 or approx $40.00 the set) has markedly better Rx even when just outside the cab, on the step for instance, and strangely seems not to be as badly affected by the bridges and pylons On Thu, 18 Aug 2005 07:59:22 -0400, "J. Mc Laughlin" wrote: Dear Mr. Stephen Parry: It is possible that the truck (it is one truck?) produces too much noise at 198 kHz. An important test is to note if your portable radio tuned to 198 kHz receives a satisfactory signal-to-noise ratio when the truck is running all of its equipment. Try placing the portable radio next to the truck in places where one might attach an antenna. The fitted radio, which has LW, must have an outside antenna. Is that antenna in good condition? Your solution might be to reduce the noise produced by the truck. Antennas for LW suitable for mounting on a truck do exist, however they will not help if they receive too much noise. Could describe one of these please?? Let the group know the results of your testing. Tell us more about the truck. Regards, Mac |
On Thu, 18 Aug 2005 10:54:21 -0500, (Richard
Harrison) wrote: Thank-you Richard for the prompt reply, which I am afraid I understood little of (! my fault not yours) Stephen Parry wrote: "I drive a truck on the continent of Europe, and would love to listen to this service on the road for cricket." The Blau Punkt in my Karman Ghia got such signals all over the continent, and I`m just one of millions. Mr Parry did not say if his truck is Diesel powered as most European trucks are. Yes Diesel power, so no HT coil, plugs, distributor etc If so, he is free of his own ignition noise, usually the hardest to suppress. Ok. He still may have alternator whine (perhaps a bad diode) Yes I think I do have alternator noise could you explain what I might do ? and he may have static discharges from things which rotate. Some are under the hood, and their radiation should be kept under the hood by the metal surrounding them. All such metal pieces should be bonded together to keep the trap they form closed. All conductors coming through or under the firewall should be well grounded or bypassed with capacitors at the firewall. The exhausr pipe may need bonding here also. I think we might have been divided by our common language! My truck has no "hood" as such http://www.duet-duda.mojagielda.pl/?9 Maybe there is a gasoline powered rerfrigeration compressor generating ignition noise. Standard resistance wires, capacitors, and bondibg should silence that. No 'fridge Springs can be used in wheel hubs to ground out static. I did not understand this part All the metal parts of the truck may have to be bonded together. Or this My Blau Punkt was equipped with a good sized choke coil in its battery lead. It also had an internal "spark-plate" capacitor, and these rid the power source of radio noise. Or this The telescoping antenna (about 50 years ago) could be extended to about 100 inches, which made the Karman Ghia quite a sight, but it worked. The antenna cable was the standard high-impedance small inner-wire coaxial type. This must be intact and perfect to keep the signal on track and the noise out. Though German, it used Motorola connectors. Radio frequencies decline very rapidly near their source. This is your friend when the source causes interference. Sorry, this too! Keep the antenna away from and shielded from sources of interferebce. When you say "bonding" I am guessing this means a clean earth return to battery? In 1935, Alfred A, Ghirardi (E.E.) wrote: "---an aerial must be installed in (or on) the roof, under the running boards or chassis of the car, or in some other locations. ---Considerable attention must be given to the ignition and other electrical wiring of the car in order to eliminate all electrical interference which it produces in the receiver." Noise problems are more often caused by the vehicle than by the receiver but some receivers may not be shielded and filtered well enough. If the truck cab has its pieces bonded together and all pass-through conductors are well bonded or bypassed, it should be electrically quiet. You should be able to use a portable radio in there with proper placement or an outside antenna. Ghirardi devotes an entire chapter to automobile radio installation in "Modern Radio Servicing". Car radios are hot in the summer months while home radios are not. Best regards, Richard Harrison, KB5WZI |
London - Vienna return more than enough! On Thu, 18 Aug 2005 12:38:44 -0400, "Fred W4JLE" wrote: Richard, can one drive far enough in Europe that the drive time would allow listening to an entire cricket match? I mean here in the states it might be possibe, say from New York to Texas etc... "Richard Harrison" wrote in message ... Stephen Parry wrote: "I drive a truck on the continent of Europe, and would love to listen to this service on the road for cricket." |
On Thu, 18 Aug 2005 10:16:30 -0500, Cecil Moore
wrote: I was referring to electrical type noise Stephen Parry wrote: Inside the steel box (cab) however, too much noise/too little signal to be useful. Is the noise coming out of the radio speaker or is it the physical noise level that is the problem? |
On Thu, 18 Aug 2005 12:35:38 -0400, "Fred W4JLE"
wrote: Fred I think you must be Psychic! current system is all 24V, yesterday went out and paid £35.00 for a DC/DC dropper so I could fit a car radio... are you saying that this will make things worse? One problem you might look at aside from all the other great suggestions is to look at how your radio voltage is derived. Most trucks are 24 volt and the radios 12 volt. Are you tapping at the junction of the two twelve volt batteries or does your truck use a 24 to 12 volt converter? These are usually really noisy from an electrical standpoint. "Stephen Parry" wrote in message .. . Hi folks, first let me apologise for not lurking, or even reading a FAQ (I did look and did not find). I know that radio amateurs are a helpful and friendly bunch, so here goes. From the UK, for historical reasons, the BBC broadcasts programmes on Long wave, specifically 1500 metres (198 Khz???). I drive a truck on the continent of Europe, and would love to listen to this service whilst on the road (for the cricket!). I know that the signal is there, and of sufficient strength, as I can receive it OUTSIDE the truck on an ancient "portable" Inside the steel box (cab) however, too much noise/too little signal to be useful. The fitted radio has LW, but again cannot be used for the noise. Could anyone please point me to some answers to the following: Antennae: Could I build (buy) some kind of antenna specifically to receive this emission? (My old radio has a socket labelled "AM antenna"). Could I build a receiver tuned only to this freq., with no need for a speaker (run the sound in at headphone type power) that I could hang/bolt outside the truck (on the roof?), with its own battery and aerial? If so could someone point me to a diagram of such a beastie? |
Crazy George wrote:
Richard: You should be advised that modern semiconductor driven diesel injectors are noisier than Kettering ignition systems. DIN and the rest of the European regulatory bunch have really clamped down on spark fired ignition noise, but apparently Diesels have escaped their attention. -- Crazy George Only too true. When mobile I can hear Mpls buses about 100 feet away over the S5 downtown noise on 20 meters. They make an interesting tone pattern that I surmise may have to do with resonances in the various lengths of the wiring harness involved. I've heard much the same from some, but not all, diesel trucks. tom K0TAR |
Crazy George wrote:
"You should be advised that modern semiconductors driven diesel injectors are noisier than Kettering ignition systems." I didn`t have a clue. My experience is out of date. Injectors were timed by a camshaft which generated little electrical noise. Methods used to control radiation from Kettering ignition systems and their solid-state derivatives should work on fuel injection timing systems too. The plan is to keep the electrical noise within a screened enclosure and not let it out. It is hard to believe there is no DIN specification for radiation from electrically timed fuel injectors. In the old days ther was a specification for about everything. Best regards, Richard Harrison, KB5WZI |
On Fri, 19 Aug 2005 07:32:25 -0500, Tom Ring
wrote: Model id Mercedes-Benz badged Truckline CC25 made I think by Becker I wonder if the radio has a trimmer capacitor like many of the US AM BCB radios have had over the years. You would normally have to pull the radio from the dash and inspect it to see. If it does, it may help a bit to tweak it. What is the model number of the unit? Maybe we can find an online user's manual. tom K0TAR |
Well, nothing in english seems to be available. There is a link to the
German ebay that will sell me one. There also seems to be something in Russian, but I can't do much with that. tom K0TAR Stephen Parry wrote: On Fri, 19 Aug 2005 07:32:25 -0500, Tom Ring wrote: Model id Mercedes-Benz badged Truckline CC25 made I think by Becker I wonder if the radio has a trimmer capacitor like many of the US AM BCB radios have had over the years. You would normally have to pull the radio from the dash and inspect it to see. If it does, it may help a bit to tweak it. What is the model number of the unit? Maybe we can find an online user's manual. tom K0TAR |
Simply tap off at the junction of the two batteries. The truck series two 12
volt batteries to give you 24. Find the the junction where the plus of one is tied to the minus of the next. Tap off a wire at this point. I would fuse it at the connection point. This will provide the necessary voltage for the radio. CAUTION! I have made the assumption that your truck has the chassis tied to the negative side of the first battery. In the event you have a positive ground truck let me know and I will tell you how to get around that problem. "Stephen Parry" wrote in message ... On Thu, 18 Aug 2005 12:35:38 -0400, "Fred W4JLE" wrote: Fred I think you must be Psychic! current system is all 24V, yesterday went out and paid £35.00 for a DC/DC dropper so I could fit a car radio... are you saying that this will make things worse? One problem you might look at aside from all the other great suggestions is to look at how your radio voltage is derived. Most trucks are 24 volt and the radios 12 volt. Are you tapping at the junction of the two twelve volt batteries or does your truck use a 24 to 12 volt converter? These are usually really noisy from an electrical standpoint. "Stephen Parry" wrote in message .. . Hi folks, first let me apologise for not lurking, or even reading a FAQ (I did look and did not find). I know that radio amateurs are a helpful and friendly bunch, so here goes. From the UK, for historical reasons, the BBC broadcasts programmes on Long wave, specifically 1500 metres (198 Khz???). I drive a truck on the continent of Europe, and would love to listen to this service whilst on the road (for the cricket!). I know that the signal is there, and of sufficient strength, as I can receive it OUTSIDE the truck on an ancient "portable" Inside the steel box (cab) however, too much noise/too little signal to be useful. The fitted radio has LW, but again cannot be used for the noise. Could anyone please point me to some answers to the following: Antennae: Could I build (buy) some kind of antenna specifically to receive this emission? (My old radio has a socket labelled "AM antenna"). Could I build a receiver tuned only to this freq., with no need for a speaker (run the sound in at headphone type power) that I could hang/bolt outside the truck (on the roof?), with its own battery and aerial? If so could someone point me to a diagram of such a beastie? |
Stephen Parry wrote:
"Yes I think I do have alternator noise could you explain what I might do?" Often the first sign of diode failure is a whine in the loudspeaker of your radio which varies in pitch with engine speed. Alternators have no commutator but use silicon diodes to make d-c from the a-c they generate. It`s usually 3-phase, using (6) diodes in (2) groups of 3 each in a full-wave rectifier. These are located inside the alternator. If any of the diodes fails, at least one of the 3 pahases quits contributing to the alternator output. Maximum output is reduced. Replace the diodes. The whine goes away and full output is restored to the alternator when required. Stephan also wrote: "I think we might have been divided by our common language!" What Americans call a hood, I believe, is what the English call a bonnet. The effectiveness of a screened enclosure depends on good connections between its pieces. In a modern diesel truck there may be noise generating electrical fuel-injection control, rotating belts which generate static discharge noise, electrical relays and contactors, and other sources of radio frequency noise. Noise containment is one goal of the bonnet. The hinge which holds the bonnet and the latch which locks it are often inadequate in r-f continuity. Their electrical contact is not good enough. Wheels rotate on stationary spindles and axles. Rotation can produce charge which repeatedly arcs across wheel bearings or other points. Spiral springs are made with a large diameter on one end to rest on a stationary part of the wheel assembly. The spring tapers down to a small diameter or point on its other end. This point makes contact with a hammer-on cap over the nut which holds the wheel on its spindle. The cap rotates with the wheel. So we have a conducting connection between the wheel and the non-rotating parts of the vehicle. Only extreme noise cases require these springs. Stephen also questioned what I meant by perfect antenna cables. I once repaired rafios and my experience is that most noisy automobile receivers got that way from defective antennas and antenna cables. The base of the antenna needs a good connection to the vehicle body, which is the other half of the antenna. The vehicle body is the connection for the cable shield. The shield needs to be continuous to carry the signal rather than having the body carrying the signal where it may be exposed to noise currents. I wrote: "Keep the antenna away from and shielded from sources of interference." When one installs an antenna, it should be placed in a quiet receiving location if possible. It should not be installed on the same side of a screen as wires carrying interference. The antenna should be installed on the outside of the truck cab where it has large exposure to the signal. When I said bonding, I did mean a clean earth return but I was not thinking of battery current. I was thinking of r-f currents, signal and noise. Radio frequencies don`t penetrate deeply into metal but travel on the surface. Large surface area is needed for low r-f impedance. Battery current uses the entire cross section of the metal. Wires slung under running boards and the chassis are not much used now. Other noisy conductors may be nearby Broadcast ground waves are vertically polarized. It makes sense to use a vertical whip for reception, though almost any wire works. Stephen`s portable likely has a loop antenna inside which makes it somewhat bidirectional in azimuth. A vehicle mey be found in any position. This makes an antenna which is nondirectional in azimuth desirable. Best regards, Richard Harrison, KB5WZI |
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