Saw an older thread (closed), so am going to add two-cents as “answer” to question asked of, is it effective?
Yes (and the rest of this a very long foot-note of context).
My experience is purely as a mobile application in big trucks where RF Noise from on-board sources and the general difficulty of best antenna-mount RF Bond are constants.
Understand that, spending as an experiment is not what I consider to be a determinant against what is considered to be successful if it doesn’t quite work out (can go in box of spare gear & supply for other systems).
I’ve had an ICE brand (formerly, Morgan Systems) 11-Meter Bandpass Filter for several years and found that it does drop the noise floor in this vehicle-type. (Under the working assumption that the antenna & coax are already as ideal as can be; vehicle RF Bonds applied; quality components otherwise; etc).
Posting this as getting ready to drill a hole in the heavy steel shelf above the windshield (KW-T680) to act as a single-point ground. Have to stop off at home to pick up a double-male coax connector and a jumper to insert the 411cb unit to ascertain whether again it’s worth the trouble to use.
This present radio system (since 8/2021) is the quietest I’ve had in a big truck thus far. About four (4) years of experiment. An assortment of gear and approaches. 12,000-hours of use, give or take.
There are several vendors and the 11M models may be available by request. The ICE 411cb is advertised as such, and due to space constraints was the the one I chose. “Better” designs are possible (circuitry). Be aware of fine-print power-handling limits.
My thoughts — initially and to the present — are that to reduce the transceiver workload is, first, a positive, and that to reduce outgoing harmonics is the other.
1). Where the radio system was already as quiet as one could make it atop the priority of a maximum TX/RX distance match (RF Bonds, primarily, once past no-noise 12V); and,
2). Given mobile use across the country (dead-silent far rural to heavy-noise metros) 300-days/year and 10-12/hrs of daily use:
— my experience is that it has been worth the trouble and expense where DSP filtration is present in the audio portion of the system.
— CB Radios lack the discrete filtering capabilities of Amateur Radio gear. DSP is a huge change where a BPF is a minor change. (A $200 AM/SSB radio so-equipped has better ears than the top $400+ radios without such).
Presently, I’ve in use some P-E coax filters at antenna feedpoints (14’ total height) and at transceiver. The BPF might be superfluous, except to bond coax nearest transceiver.
Have posted this as noise in a mobile system can seem impossible to tame having been diligent via best practice: I wonder if that’d help?
A qualified Yes
Noise Control (abatement) is sorta like clearing underbrush from the forest. The trees stand out better, afterwards. DSP is a BIG change (don’t leave home without it), while a BPF is a lot more of a maybe.
It works to ease the life of the transceiver, but can you take advantage of the little that’s on offer?
As I relish the ability to audibly capture those faintest signals, I’m happy with the marginal success. My job has DIRECT effects from knowing road-related problems.
The faint signals captured may be a couple of rock-haulers with low-dollar rigs trading info about the route I’m on. Well off of the main road while getting re-loaded . They’re just exchanging some short-hand notes. (Believe me that they’re NOT heard by 99% of other truck drivers)
Those short-hand notes are a wake-up to me to start making inquiries. With EVERYTHING I’ve got. Timeliness, Safety, and Stress-Level are all at stake before the question of net income.
Is your job one where if you screw up, people die?
The total $$ in my radio system is above and beyond what private vehicles require to match or exceed a composite-body big truck in performance. Easily twice (four figure). So adding 5% more doesn’t seem like much.
Yeah, I’d recommend the experiment (ARRL guides to same for DIY), but not without trying everything else first (repeatedly, till proven) but ain’t gonna listen to crying, as in your use it may not matter at all.
Mobile Install Bible
Is the source of HOW to exhaust every angle beforehand.
Someone else will kindly explain the use of a BPF in Amateur Contesting, etc. The “normal” reasons for this acquisition.
.
Yes (and the rest of this a very long foot-note of context).
My experience is purely as a mobile application in big trucks where RF Noise from on-board sources and the general difficulty of best antenna-mount RF Bond are constants.
Understand that, spending as an experiment is not what I consider to be a determinant against what is considered to be successful if it doesn’t quite work out (can go in box of spare gear & supply for other systems).
I’ve had an ICE brand (formerly, Morgan Systems) 11-Meter Bandpass Filter for several years and found that it does drop the noise floor in this vehicle-type. (Under the working assumption that the antenna & coax are already as ideal as can be; vehicle RF Bonds applied; quality components otherwise; etc).
Posting this as getting ready to drill a hole in the heavy steel shelf above the windshield (KW-T680) to act as a single-point ground. Have to stop off at home to pick up a double-male coax connector and a jumper to insert the 411cb unit to ascertain whether again it’s worth the trouble to use.
This present radio system (since 8/2021) is the quietest I’ve had in a big truck thus far. About four (4) years of experiment. An assortment of gear and approaches. 12,000-hours of use, give or take.
There are several vendors and the 11M models may be available by request. The ICE 411cb is advertised as such, and due to space constraints was the the one I chose. “Better” designs are possible (circuitry). Be aware of fine-print power-handling limits.
My thoughts — initially and to the present — are that to reduce the transceiver workload is, first, a positive, and that to reduce outgoing harmonics is the other.
1). Where the radio system was already as quiet as one could make it atop the priority of a maximum TX/RX distance match (RF Bonds, primarily, once past no-noise 12V); and,
2). Given mobile use across the country (dead-silent far rural to heavy-noise metros) 300-days/year and 10-12/hrs of daily use:
— my experience is that it has been worth the trouble and expense where DSP filtration is present in the audio portion of the system.
— CB Radios lack the discrete filtering capabilities of Amateur Radio gear. DSP is a huge change where a BPF is a minor change. (A $200 AM/SSB radio so-equipped has better ears than the top $400+ radios without such).
Presently, I’ve in use some P-E coax filters at antenna feedpoints (14’ total height) and at transceiver. The BPF might be superfluous, except to bond coax nearest transceiver.
Have posted this as noise in a mobile system can seem impossible to tame having been diligent via best practice: I wonder if that’d help?
A qualified Yes
Noise Control (abatement) is sorta like clearing underbrush from the forest. The trees stand out better, afterwards. DSP is a BIG change (don’t leave home without it), while a BPF is a lot more of a maybe.
It works to ease the life of the transceiver, but can you take advantage of the little that’s on offer?
As I relish the ability to audibly capture those faintest signals, I’m happy with the marginal success. My job has DIRECT effects from knowing road-related problems.
The faint signals captured may be a couple of rock-haulers with low-dollar rigs trading info about the route I’m on. Well off of the main road while getting re-loaded . They’re just exchanging some short-hand notes. (Believe me that they’re NOT heard by 99% of other truck drivers)
Those short-hand notes are a wake-up to me to start making inquiries. With EVERYTHING I’ve got. Timeliness, Safety, and Stress-Level are all at stake before the question of net income.
Is your job one where if you screw up, people die?
The total $$ in my radio system is above and beyond what private vehicles require to match or exceed a composite-body big truck in performance. Easily twice (four figure). So adding 5% more doesn’t seem like much.
Yeah, I’d recommend the experiment (ARRL guides to same for DIY), but not without trying everything else first (repeatedly, till proven) but ain’t gonna listen to crying, as in your use it may not matter at all.
Mobile Install Bible
Is the source of HOW to exhaust every angle beforehand.
Someone else will kindly explain the use of a BPF in Amateur Contesting, etc. The “normal” reasons for this acquisition.
.
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