Getting the Icom IC-735 Online and on the Air

The Icom IC-735 is a compact HF transceiver aimed at operators who want something smaller than their old flagship but without dropping down into toy territory. It covers 1.8–54 MHz, runs 100 W on SSB and CW, and comes with a built-in tuner, Bluetooth, and a color display. The manual that ships with it is thin — about 60 pages in the quick-start version, longer if you grab the full PDF — and it leaves out a lot of the nuances that matter once you actually try to set it up. Here’s how I got one running properly, and what I wish the manual had said up front.

Where to Find the Icom Ic 735 User Manual

Icom hosts the full documentation on their support site. The file is titled “IC-735 OPERATING INSTRUCTIONS” and lives under the manual download section for that model. If you’re just starting out, the Quick-Reference Guide is fine for the first hour. But the full operating instructions are where you’ll find the menu tree, the tuner settings, and the Bluetooth pairing steps that the shortcut card glosses over. I printed the full PDF because I keep losing my place when I’m chasing a particular setting while a contact is still on the frequency. You don’t need to register the radio to download it. The PDF is publicly available and Icom doesn’t gate it behind an account.

Powering Up and Basic Setup

Plug in the supplied power cord, connect an antenna — any broadband HF antenna will get you moving — and flip the power switch. The radio boots into a default state that’s usable immediately but far from optimal. The first thing I do is set the AGC to slow. The default is medium, which sounds fine until you’re listening to a crowded band and the gain rides up and down like a heartbeat. Slow AGC steadies the audio and makes copying weak signals a lot easier, especially on CW. Next, set the RF gain. The manual tells you to adjust it, but it doesn’t tell you that if you leave it at maximum you’ll hear noise from the front end that isn’t actually coming from the antenna. I learned this the hard way during a summer band opening when my noise floor was so high I thought the rig was broken. Dropping the RF gain to about 60 percent killed the hash and the signal stayed strong. The mic gain should be set using the S meter while you talk. Aim for the meter to pulse around the 3–4 mark on a normal speaking level. Overdriving the mic sounds harsh and will push your reported signal into the 9+ range, which most operators will notice as distortion. Underdriving sounds thin and gets lost in QSB.

The Tuner — Actually Using It

The built-in tuner is one of the reasons this radio sells well, but the manual doesn’t make it clear how to get consistent results. Here’s what works: Set the antenna mode to the type you’re using. If you’re running a random wire or end-fed half-wave, select “Random Wire” or the equivalent in the tuner menu. If you’re using a standard dipole or vertical, pick the matching option. The manual lists these but doesn’t explain that picking the wrong one can cause the tuner to overcompensate and give you a poor match even when the antenna is fine. Press the ATU button. The radio will sweep and display the SWR after tuning. If it can’t get below 1.5:1, you’ll see a failure message. At that point, check your antenna connections and try again. Loose PL-259s and corroded SO-239s are the most common cause of tuner failures, not actual antenna problems. I keep the tuner in “Auto” mode most of the time. There’s a manual tune option, but it’s tedious and rarely necessary unless you’re doing something like adjusting a trap dipole while transmitting.

Bluetooth and the Headset Question

The IC-735 has Bluetooth built in, which sounds like a gimmick until you’re working portable and don’t want a separate headset. The manual walks through pairing, but it doesn’t warn you about latency. When you speak into the BT mic, there’s a noticeable delay before your audio comes back through the rig’s speaker. That delay is fine for casual operation but annoying if you’re trying to break into a pileup. I found that pairing the radio to a Bluetooth PTT footswitch is more useful than pairing a mic. You can talk through the built-in mic and step the radio with your foot. Saves wear on the hand and keeps you from accidentally muting yourself by bumping the mic cord. The manual also omits the fact that Bluetooth audio quality is compressed. If you’re listening to music or doing contest working with critical audio, plug in wired headphones. The Bluetooth codec won’t do you any favors for SNR.

Common Settings I Change From Default

The radio comes configured conservatively. That’s intentional, but it means you’ll want to tweak several things before regular use.
  1. AGC: Set to Slow for SSB and CW. Fast is okay for RTTY if you’re decoding digitally, but it makes everything sound choppy.
  2. BPF: Set to “Auto” so the radio selects the right bandwidth filter for the mode you’re in. You can set it manually, but that’s rarely worth the effort.
  3. NB (Noise Blanker): Turn it on only when you’re actually hearing impulses. Leaving it on all the time degrades weak signal audio and makes SSB sound brittle.
  4. NR (Noise Reduction): Use sparingly. It smears audio in a way that’s more annoying than helpful for most operators.
  5. Split Frequency: The manual explains the function but not the workflow. I use split constantly when working DX. Set the TX frequency, listen on RX, and toggle split with the dedicated button. It’s faster than digging through menus.

A Real Problem I Ran Into

About three weeks after I got the radio, I noticed that the display would occasionally go blank for a second while the radio was still transmitting. No error message, no reboot, just a momentary blackout. I suspected the power supply because I was running it off a small 12 V battery and the current draw during transmit is roughly 20–22 A at 100 W. The manual doesn’t mention display glitches at all. I contacted Icom support and they pointed me toward the power connection. I upgraded from a set of alligator clips on a lead-acid battery to a proper 30 A power supply with voltage regulation, and the issue disappeared. The lesson: the IC-735 is sensitive to Brownian voltage sag under load. Cheap supplies cause weird behavior that looks like a hardware fault but is really just the radio brownouting momentarily. If you’re experiencing intermittent display resets or the radio dropping keys, check your power delivery before assuming the rig is defective.

Operating Tips That the Manual Skips

The IC-735 has a narrow CW filter option that’s genuinely useful. The default CW bandwidth is around 500 Hz, which is fine for most work. But switching to the 250 Hz filter when conditions are good and you’re trying to pull a weak signal out of the pileup makes a measurable difference. The manual mentions the filter but doesn’t emphasize how much narrower you can go without losing intelligibility. Another thing the manual doesn’t cover: the radio remembers your last frequency and mode when you turn it off. This is useful but can also catch you off guard. If you leave the radio on a congested frequency and come back later, you’ll resume exactly where you were. I’ve had this cause me to accidentally transmit on an occupied frequency twice. Always verify the frequency before PTT, especially after a break. The VOX function is present but not great. The threshold adjustment helps, but the hang time is too long for fast CTY operators. I keep VOX off and use the PTT switch on the mic.

Transmit Power and Legal Limits

The IC-735 puts out 100 W on HF bands where your license permits it, 50 W on some segments depending on region, and lower power on 6 meters and above. The manual lists the legal output limits for each country, but it doesn’t make it clear that the radio will attempt to deliver full power even if your antenna system can’t handle it. Always check your SWR before transmitting at full power, and back off if the tuner is working hard to match a poor antenna. For portable operation, I usually run 50 W or less. The radio handles lower power cleanly, and most QSOs don’t require full lineup. Lower power also reduces heat and extends battery life, which matters when you’re operating from a car or a small generator.

Downsides and Where It Falls Short

The IC-735 isn’t perfect. The keyboard is small and the menu system takes time to navigate. If you’re used to the larger rigs with dedicated knobs for every function, you’ll find yourself digging through sub-menus more often than you’d like. The screen is bright and colorful, which is nice, but it’s not as sharp as the displays on higher-end Icom models. The Bluetooth mic is optional and sold separately. If you’re buying the radio specifically for Bluetooth operation, budget for the accessory. The built-in mic is serviceable but not great for noisy environments. There’s no built-in digital mode interface beyond Bluetooth audio. If you want to run FT8 or PSK31, you’ll need an external interface or a USB connection to your computer. The manual mentions the USB port but doesn’t provide detailed software integration steps.

Summary

The Icom IC-735 is a capable compact HF transceiver that rewards operators who take the time to configure it properly. The included manual covers the basics, but the real functionality — AGC settings, tuner optimization, filter selection, power management — comes from experience and a willingness to dig into the menus. The full operating instructions PDF is worth reading cover to cover before you start operating regularly. Once you do, you’ll find the radio is stable, responsive, and well-suited for both home station and portable use.