Part of our The Icom IC-7300 Mark II: The Complete Guide.
The Mark II’s lower standby draw is a nice improvement, but full transmit current still demands a real power supply, not whatever wall wart happens to be nearby. Here’s what actually matters.
Current headroom, not just the number on the box
Check the radio’s actual transmit current draw at full 100W output, and pick a supply with real headroom above that, not one that’s barely rated for peak draw. A supply running near its limit is more prone to voltage sag exactly when you need clean power the most, mid-transmission.
Linear versus switching supplies
A quality switching supply is generally fine and more compact, but cheap switching supplies are a common source of broadband noise on receive. If you notice a noise floor that wasn’t there before after adding a new supply, that’s the first thing to suspect. A linear supply avoids this concern entirely at the cost of size and weight.
Clean connections matter as much as the supply itself
Use appropriately heavy gauge power cable and secure connectors, a marginal connection under load causes the same voltage sag symptoms as an underpowered supply even if the supply itself is perfectly capable.
What to actually check
- Confirm your supply has real current headroom above the radio’s full transmit draw.
- Listen for new receive noise after adding any switching supply, and address it early if you hear it.
- Use properly sized cable and secure connectors between supply and radio.
- Keep the supply itself away from antenna feedlines if it’s a switching type, to minimize noise coupling.
A radio with this good a receiver deserves a power supply that doesn’t undermine it with noise or sag right when you need clean performance the most.