My new radio seems to work as advertised, but when I set the power level to 100%, I expect the current draw to be near 20 amps or so. Instead, the current draw from the power supply is 5-6 amps. Also nobody can hear me unless they are in town and nearby. Seems to be a correlation here. Since I am fairly new to HF radio, I don't have details like this in my head, ready to be used on short notice. My old radio (RIP) also drew small currents and didn't do well, but I thought it was just the old radio. I have a vertical antenna in the backyard which seems to be set up correctly, and I have checked all the cables in use. So, the question is, (finally), is 5 watts normal, or is something screwing up?

 

You need to provide a lot more detail to have any hope of getting a meaningful response.

The radio's make and model would be a good place to start.

You say that it draws 5-6 amps, but then ask whether 5 watts is normal. Amps and watts are not remotely interchangeable. What is the voltage of the power supply you are talking about. It would be 5 W only if the supply is 1 V, which is very unlikely.

As for what's normal, that depends on the radio, and so again, you really need to provide more information.

 

Welcome to AAC.

While you can't possibly have more output than input using current draw to determine RF output is like trying to determine the speed of your car by looking at the fuel consumption gauge—you can't.

First, as @WBahn said, more detail is required. Make and model the radio at the very least but also:

• make and model of the power supply
• how you have them connected (i.e.: length and gauge of the connecting wire)
• how you are measuring the current

If you want to know the output power of your transmitter, you need to measure that with an RF power meter. Current draw certainly indicates the possible upper limit (e.g.: assuming 13.8V supply, 5A would mean [13.8 x 5=]69W. On the other hand, even with a 12V supply, 20A would be 240W).

Based on this, and the SWAG that you have a 100W radio, and the 20A is for full output, the output at 5A could reasonably be expected to be ~25W. If, for example, you have the PS wired to the radio with long, small diameter wire, the voltage drop caused by the resistance it presents could act as a current limiter and prevent the PS from supplying the current required for full output.

 

Thank you to both of you for a quick answer, even though the question gave you little to go on.
Sorry about the minimal information - I had been fighting several problems, including this one, all day. Here is the equipment list:

Icom 7300 (new) Radio, set to 100% power for testing
MFJ4225MV power supply
MFJ4230MV power supply
RG8X cable to antenna, 50 ft
Hy-gain 18AVQII antenna

cable from PS to radio is about 3 ft long at 12 ga.
Both power supplies have volt and amp meters, which is how I measured amps drawn.
Both power supplies are set to 13.2 volts, below the capability of the PS's.
I list both PS because I was comparing them to see if I have a PS problem. Both gave the same results.
I used the internal tuner to tune the antenna.
I measured power out by setting the radio to CW and keying the mike.
The use of watts in the last sentence is in error - it should be 5 amps.
I use 20 amps as a max amps for the PS because all the HF radios advertised say that a 23 watt PS is required.

NEWS FLASH!!
I found my MFJ-864 SWR Wattmeter and connected it to my antenna and RF out. As far as I can tell, there is nothing coming out of the radio. I found another SWR meter and got the same result. What is puzzling is that I made an in-state contact (200 miles) the first night I had the radio connected up, and he seemed to hear me just fine. Then I made a nearby contact on the second night - nothing seemed unusual. On the third night I tried to check in to the same net, this time about 5 miles away, and I got no response. That is when I started troubleshooting with the above results. I think the 5 amp rise on keying up is the internal draw, but with no output. So, on with the digging.

Bob

 

Both power supplies are set to 13.2 volts, below the capability of the PS's.
I list both PS because I was comparing them to see if I have a PS problem. Both gave the same results.
I used the internal tuner to tune the antenna.
I measured power out by setting the radio to CW and keying the mike.
The use of watts in the last sentence is in error - it should be 5 amps.
I use 20 amps as a max amps for the PS because all the HF radios advertised say that a 23 watt PS is required.

You still seem to be equating amps with watts.

You have a 13.8 V power supply. If you draw 20 A from that, you are consuming 276 W. A 13.8 V power supply delivering 23 W is only supplying 1.7 A.

The Manual for the Icom 7300 says that it's max current draw for the transmitter is 21 A (from a 13.8 V supply).

 

You are right - I have watts on the mind. It should be amps. What is a good way to get the radio to draw max amps? With my last radio, I just set the radio to CW, set the output to 100 %, and then keyed up the microphone. I don't know if that works with this radio. The manual entry showing max current at 21 amps is what I have been working from. But how do you get the radio to do that?

Thanks
Bob

 

With my last radio, I just set the radio to CW, set the output to 100 %, and then keyed up the microphone.

The Up/Down buttons can be used as a cheap way to key the radio in CW but only if turned ON in the menu.

But how do you get the radio to do that?

Connect a dummy load, switch to FM, set full power and push PTT.

The radio is able to measure and show you the drain current ID of the MOSFETs in the power amp stage if you expand the multi-function meter.

 

Thanks to everyone who took the time to help me with my problem. It turns out that the radio is functioning just fine - the operator - not so much. Jeff w5abq called with the particular help I needed. It was a combination of misreading the power supply meter and trying to get the radio to transmit on CW with the microphone key - it doesn't do that. 0ri0n showed one way to do that. You can also do it by using FM or AM with full power set. So I don't have to send my radio back. On to the ether.
Bob in Querque

 

I have only known one ham who can send CW on the tone keypad of an HT. But he was an EXTRA with a 2 by 1 call., so he was allowed to do that.
It is often very useful to read the manual that comes with the radio!!!

 

Have you checked the RF gain control on the radio?