# Tag Info

9

A 50W transmitter is one that can create 50 watts of RF output. The RF amplifier is never 100% efficient, so the input power requirements will always be higher than the output power. Furthermore, the maximum current drain accounts for startup transients and other peaks in excess of the average current drain.

8

Firstly, there's a hole for a locking pin in the connectors. The pin prevents the connectors from sliding apart. If there's a pin in there, you'll need to push it out with a punch. If there isn't a pin, it's possible the connector was assembled with cyanoacrylate glue. Since the roll pin can sometimes fall out, Anderson recommends glue in applications where ...

7

There are two reasons for the advice to run direct to the battery: Minimize the area enclosed by the power connections. This reduces both interference picked up by the wiring, and inductance (which is undesirable in power supply connections). Minimize resistance. A radio can be a fairly heavy load as car accessories go, so you want to avoid any voltage drop ...

7

The answer is a resounding yes. How you do it depends on whether you are mobile (like in an RV) or stationary. Here is a video answer from David Casler, KE0OG, the Original Genius, who both answers the first question and also the second. This video is a good introduction. Key fact that must be stressed: A solar charge controller is required to properly ...

7

I don't mean to talk you out of the idea, but I suspect the advantages are not nearly so great as you imagine. Cheaper than a dedicated RF-grade power supply (USD30 for 40 Ah car battery) I don't know about that. While there are certainly people selling "RF-grade" supplies at high prices because there are people that will pay, we're not talking ...

6

The plug used in the Baofeng base is a 5.5 mm/2.1 mm barrel connector. However, you cannot simply parallel a bunch of base charger units and power them off of a single AC or DC adapter without properly considering the total current required. The stock AC wall wart for the charger puts out 10 volts at 0.5 amps. Each charging base will require 0.5 amps. So, ...

6

The only reason to use a linear power supply is to reduce electrical noise (or if as an exercise in electronics you want to build your own power supply without using integrated circuits, or if you need your equipment to double as doorstops). It is also quite possible that if you do want to reduce noise, you will be better served by adding filters to, or ...

6

If I understand the description correctly: simulate this circuit – Schematic created using CircuitLab If that's all it is, I wouldn't say it's any big deal. Whenever you have multiple paths to ground, current will split between them. It's these currents that keep "ground" approximately the same voltage everywhere: an essential assumption in the ...

6

I used LiFePO4 (read: Lithium Iron Phosphate) for my dad's FT-891. The big advantages of LiFePo4 are: Very power dense, almost as much as Li-Ion, IIRC twice as much Wh/kg than Lead-acid Extremely safe: they don't short circuit themselves to flames, like Li-Ion does Flat voltage discharge characteristics: their nominal voltage is 3.2V and they stay at 3.2V ...

5

From http://rallynotes.com/2017/03/12v-anderson-powerpoles/: This is a good image for orientation reference.

5

Possibly an issue with your HF CB rig is that the output power will be lower at 12.1 than at 13.8 or 14.0 volts. I've seen on 100 watt ham rigs that the final amplifier runs directly from the DC supply, so the output power is quite sensitive to the supply voltage. So you might lose out on a few watts running from battery. This probably won't apply to the UHF ...

4

The most convenient power source would in fact be the lead-acid battery. However, not carried by hand, but in a vehicle. This provides an easy source of recharging power (just start the car), mobility to quickly relocate (driving), and the lead acid battery does have enough amperage to power most field radios (100 W+). As a lighter alternative, a Lithium ...

4

According to Alan K0BG's page about wiring, the negative lead is fused because of the possibility of a faulty ground elsewhere in the vehicle, which could cause excessive current to flow in the negative lead to the radio. Here's a diagram from Alan, showing how to properly wire power to the radio: Alan's page about wiring, and the rest of his site, are ...

4

There are two things I like to highlight: 1) You are thinking of putting the radio in the same glove box as the inverter; hence you may need extra ventilation/circulation to ensure neither equipment will over heat 2) Usually inverters have fuses built into the inverter, which means that the cables between battery and inverter are unfused (fused at the far ...

4

I wouldn't risk directly connecting a 9.6v battery to a radio that expects 5-6v. The simplest solution would probably be the diodes mentioned in the comment to your question, but as the battery voltage dropped the voltage reaching the radio would drop as well, and as the battery got low the output voltage after the diodes might be too low to power the radio,...

4

An anecdote: I had problems with my station which included computer-radio interconnections; some of my devices (RTL-SDRs) would lock up when I powered on my Yaesu FT-897. I eventually tracked this down to the power-on inrush currrent of the radio passing through coax shields and the chassis of the antenna switch that both were connected to. I solved the ...

4

It makes a difference of: $$10 \times \log_{10}\left(3 \over 5\right) = 2.2 \:\mathrm{dB}$$ How big is 2.2 dB? See How big is a decibel? It's also relevant to note: if the 12V battery is lead acid, the charged voltage can be as high as 13.7. Furthermore, while a boost converter might further increase your transmit power, it's likely to make noise which ...

4

In addition to the points raised in the other fine answers, I'd like to add a few: A good three-stage battery charger for lead-acid batteries may cost more than a power supply. Many chargers make horrific RF noise, so you may not want to operate while the batteries are charging, or you may want to pay more for an RF-quiet charger. The actual capacity, as ...

3

When they installed solar on my house, I lamented how Hurricane Sandy came, and yet all of the people having solar on their house could not use it because of the anti-islanding law(s) which say that your solar system, which usually pumps its excess power into the grid, must not do so when the grid is down, to prevent from electrocuting electric company ...

3

This is sort of an "it depends" question, and you noted that yourself in your text I believe. It will take some Q & A with yourself to come to a conclusion. First: What is the "field" situation. a. A literal field? b. The side of the road? c. A shelter in place situation with no grid mains? d. Pure mobile/portable on the move? Second: Based on "...

3

Note that even when not transmitting, a transceiver will draw power for the receiver, audio amplifier, control panel processor and display, etc. That idle power adds on top of the power sent thru the antenna output connector divided by the amplifier efficiency (the rest of that power/energy heating up the shack).

3

You've pretty much hit the nail on it's proverbial head: Both are power supply architectures, and as such generally fulfill the role of providing a constant-as-necessary voltage source (or current source, for some applications, but we're most likely talking about voltage sources). Now, you can imagine a linear power supply simply as a self-adjusting ...

3

Yes, it's possible. Photovoltaic panels convert solar radiation to electrical power. Why wouldn't it be possible to run a station, or any other electrical device, on solar power? Most amateur radio equipment can run on a 12V battery, usually lead-acid. Conveniently, charging 12V lead-acid batteries is a very common application for solar panels. So the usual ...

3

If by “a regulated power supply” you mean specifically a non-switching one as your second paragraph, then “a regulated power supply” and “an AC/DC adapter (linear, non-switching)” are exactly the same thing. Types of power supplies There are basically only three categories of Things You Plug Into The Wall And Get DC Out: Unregulated linear power supplies. ...

3

The circuitry in a standard radio transceiver will probably draw around an amp while it is powered on - this includes the CPU, display and other such things that are always running. Handheld radios obviously try to keep this current as a minimum, because they run on batteries. While receiving, there is also the power used by the receiving circuitry, and the ...

3

Sealed lead acid batteries are heavy. I would not recommend them. lithium phosphate or lipo are lighter, but can be hazardous. in case of physical damage to the battery they can burst into flames or even explode. Lithium Iron Phosphate batteries are also light weight and are much safer. Bioenno is a well known battery vendor that has a wide selection of ...

3

Those "wall wart" style power supplies are likely to lack the power needed here. As others point out here the radio will likely somewhere between 1.5 to 2 amps to operate as intended. I don't recall seeing a 12 volt wall wart that can provide more than 1 amp. Do you have a "soap on a rope" kind of power supply in your parts bins? That ...

3

If you haven't done much QRP operating, QRP is a funny thing. Sometimes propagation is great, and you wonder why anyone would bother with 100 W or more. I'll never forget my first DX QSO, from Oregon to Estonia, running 11 W to a vertical, by gray-line propagation at the bottom of the sunspot cycle in 2006. Other times it seems like a complete waste of ...

2

I would suggest an LM7805 type regulator. It will put out 5 volts for up to one amp current draw. You will need a filtered DC power source of 7 to 12 volts and a heatsink for the regulator. The 7805 regulator is quite common and very inexpensive. This type of supply is called a linear supply. It is not as efficient as a switching type supply but you avoid ...

2

Any type of cable will be just as good or bad at avoiding RF pickup no matter what signal it is used for. The frequency of the intended signal on a transmission line does not change the way it interacts with outside radiation. Therefore the amount of RFI getting into your device as a result of the cable attached is the same regardless of whether the cable ...

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