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#1
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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? |
#3
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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 |
#4
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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." |
#5
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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." |
#6
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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 |
#7
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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 |
#8
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#9
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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 |
#10
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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 |
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