VIDEO REVIEW
I have been using the Yaesu FTX1 for about a month and I am increasingly impressed with its receiver. Whether you own the compact 10 watt Field version or the Optima with the built-in amplifier, the receiver architecture is remarkable and gives a very quiet, pleasant listening experience. In this article I will explain what makes the FTX1 so good on receive, compare it to the FT-710, and walk you through practical tweaks you can try to get the cleanest performance from your own radio.
FTX1 models and what they offer
The FTX1 is available in two forms:
- FTX1 Field – A 10 watt transceiver, lightweight and portable, ideal for portable operation where battery life and size matter.
- FTX1 Optima – This includes the amplifier unit and delivers 100 watts on HF and 50 watts on the VHF bands. It also features a built-in antenna matching unit and two rear antenna sockets so you can switch antennas quickly.
Whichever version you choose, the receiver chain beneath 48 MHz is fully SDR. That is one of the main reasons the FTX1 delivers such an excellent listening experience. The Optima adds the extra power and integrated matching for serious base or mobile use, but the receiver itself is the same high-quality design in both models.
How the FTX1 compares with the FT-710
When Yaesu released the FT-710 it felt like a step change in receiver design. I said back then that it was "a completely new design" and that "on the receive side, it's very near the top of the Sherwood engineering ratings." The FTX1 uses essentially the same receiver concept and you will notice the similarity immediately when you switch it on.
Listening to the FTX1 alongside older transceivers, the difference is striking. The background hiss is lower, and overall the radio sounds quieter and cleaner. Several experienced hams I spoke to agree that the receiver performance here is top notch and in many circumstances indistinguishable from the FT-710.
What does "quiet receiver" really mean?
When I talk about a "quiet" receiver I am referring to how the radio handles signals across the dynamic range and how much unwanted noise ends up in the audio path. A quiet receiver is not necessarily less sensitive. Rather, it has a very good dynamic range which means the receiver can handle very strong signals while still revealing weak signals without compressing them into the background noise.
Dynamic range matters because if the front end is compressed the background noise floor moves closer to signals you want to hear. The result is that weak signals and noise are closer together and harder to distinguish. The FTX1's design increases dynamic range and avoids that compression, so strong signals remain strong and weak signals remain weak in a way that keeps the noise floor low.
Audio compression analogy
To explain it simply, think of audio compression in music production. Compressors make quiet parts louder and loud parts quieter to produce a more even perceived volume. In ham radio that is the opposite of what we usually want. We want to hear the strong desired signal clearly and we want the noise to remain low. The FTX1's design avoids unwanted compression in the RF path so you get a more natural separation between noise and signal.
Key technical reasons behind the quiet performance
There are several technical choices in the receiver design that contribute to the improved apparent performance. These include:
- Fully SDR front end below 48 MHz.
- Good dynamic range.
- Steep-sided filters.
- Band-pass filtering at the front end.
- Low-noise signal path.
This allows for precise digital filtering and very clean signal processing before audio is produced.
The radio handles very strong signals while still resolving weak ones, largely because of careful front end design and use of IPO to prevent unnecessary gain at the start of the chain.
SDR technology makes it straightforward to implement narrow, steep filters that remove out-of-band and adjacent interference more effectively than many traditional analog filters.
The transceiver uses band-pass filters tuned to amateur bands to prevent strong out-of-band signals from saturating the receiver.
All of the digital and analogue stages have been optimised to minimise internal noise contributions.
Why band-pass filters at the front end matter
An antenna connected to your transceiver can pick up signals across a wide frequency range. Without any front-end filtering those signals can swamp the receiver or create intermodulation products. The easiest way to reduce the number of unwanted signals entering the receiver is to use band-pass filters that limit the signals presented to the front end to just the amateur band you are using.
On the FTX1 the engineers have implemented band-pass filters that are narrower than general coverage approaches. That is why the handband performance is better than when you switch to general coverage. General coverage necessarily broadens the front end and some of the additional strong signals can degrade apparent performance.
Steep-sided SDR filters and why they help
As the signal moves further into the receiver chain the next place noise is reduced is by using steep-sided filters close to the tuned frequency. This is where SDR excels because digital filters can be made much steeper and cleaner than many practical analogue implementations. Narrowing the filter reduces bandwidth and with it the integrated noise. For SSB you can safely reduce bandwidth by several hundred hertz without making the signal unintelligible, but the noise reduction can be dramatic.
Practical adjustments to improve receiver performance
Even with a superb receiver like the FTX1 there are several practical settings you can change that will improve the apparent noise level and overall receive clarity. Below are the most effective adjustments I recommend testing. Try them one at a time so you can hear the difference each makes.
- Use IPO for best front end behaviour
- On HF bands when you have a decent antenna that already gives adequate sensitivity.
- When the band has multiple strong signals and you are experiencing desensitisation or intermodulation products.
- On 12 metre and 10 metre bands you may need additional gain to pick up weak VHF-propagation signals.
- On 4 metre, 2 metre and 70 centimetre bands you will often want the preamp to increase sensitivity.
- If you are using a short, inefficient antenna and you need more RF gain at the front end.
- Try the attenuator on noisy bands
- On 80m and 40m, switch the attenuator in and listen to the background.
- If the overall noise floor drops and weak signals become more discernible relative to noise, keep the attenuator in.
- If you need maximum sensitivity and there are no overload problems, switch the attenuator off.
- Use RF gain correctly
- Press the audio gain knob once to select RF gain control.
- Reduce RF gain a little and observe whether the signal of interest remains readable while the background hiss drops.
- Use RF gain as a fine control to shape the apparent noise floor when you do not want to alter other receiver settings.
- An interesting experiment: Switch AGC off
- Turn your audio gain down to a low level before switching AGC off to avoid sudden loud audio peaks.
IPO stands for intercept point optimisation. In practice this setting minimises front-end gain and improves the dynamic range, preventing overload and intermodulation when there are strong signals. Make sure IPO is selected rather than using either of the preamplifiers if you want the cleanest front end.
When to use IPO:
When to use preamps instead of IPO:
The attenuator reduces the strength of all signals entering the receiver. That may sound counterintuitive if you are looking to receive faint stations, but on crowded lower frequency bands such as 80 metre and 40 metre the sheer number of strong signals can cause front-end compression, spurious responses and a higher noise floor. Turning on the attenuator can restore clarity by reducing overload.
Practical approach:
Many operators leave RF gain fully clockwise most of the time, but that is rarely the best approach. The FTX1 lets you control RF gain easily by pressing the audio volume knob once to access RF gain. Turning RF gain down reduces the level of weaker signals and noise more than it affects the stronger signals you want to hear, which can improve signal-to-noise ratio in many cases.
How to use RF gain:
This experiment is a little old school but can be a pleasant listening experience. Automatic gain control, or AGC, tends to raise the noise level during quiet moments between signals and compresses signal dynamics. By turning AGC off you restore a more natural difference between signals and noise, and when tuning between stations the noise floor may remain much lower.
Important safety note before you try this:
Step by step AGC off experiment:
- Reduce the audio gain to a comfortable low level.
- Press the audio gain knob once to select RF gain control so you can use it to balance the incoming signal level.
- Switch AGC to Off in the AGC menu.
- If the signal you tune to is distorted when AGC is off, lower RF gain slightly until the signal sounds clean.
- Tune across the band and notice how the noise floor behaves in gaps between signals. Often the noise level will be much lower with AGC off.
Things to be aware of:
- With AGC off, rapidly varying or fading signals will change volume and may be less comfortable to listen to.
- You may need to constantly adjust RF gain when weak signals fade or strengthen suddenly.
- This mode is best for listening and for people who like to manually control their audio experience. For contesting, ragchews or when you need stable loudness AGC on can still be preferable.
Why the S meter can become misleading
When you start to manually manipulate RF gain and AGC you may find the S meter becomes a less meaningful indicator of what you are hearing. This is because the S meter measures signal strength at a particular point in the receiver chain while your manual controls alter the relative levels that make it to the speaker. Ignore the S meter while you are experimenting and judge changes by ear.
Bandwidth tweaking with SDR filters
One of the huge advantages of an SDR receiver is how easy it is to change the effective bandwidth around the tuned signal. For voice SSB you will normally use a bandwidth wide enough to preserve intelligibility. However, tightening the passband by a few hundred hertz can dramatically reduce hiss and adjacent noise with minimal impact on the voice quality.
Practical tips:
- For typical SSB voices, try reducing the passband by a few hundred hertz and listen for noise reduction.
- If the voice becomes tinny or loses naturalness, open the bandwidth slightly until the tone returns to something acceptable.
- For CW operations you can use very narrow bandwidths to reduce noise and improve copy of weak CW signals.
General coverage versus handband performance
Remember that many transceivers, including the FTX1, are optimised for amateur bands. The front-end filtering is tailored to give best performance on the ham bands and general coverage will often be slightly noisier or less selective. That is by design. If you need excellent performance on a particular segment outside the ham bands you should be aware that the radio may not be as heavily filtered in that mode and you might need external filtering to match the ham-band experience.
Other potential tweaks and future topics
There are a number of further adjustments and advanced features that you can use to tune the FTX1 to your preference. I will cover these in detail in a separate piece, but they include things like DSP noise reduction parameters, notch filters for stubborn carriers, AGC time constants, and using external preselectors in high RF environments. The basic steps I outlined above are the quickest and most effective for most users looking to improve apparent receiver noise right away.
Summary and recommendations
In short, the FTX1 is a superb transceiver and its receiver section is absolutely excellent. The combination of a fully SDR front end below 48 MHz, steep-sided digital filters, carefully designed band-pass front-end filtering and low-noise signal paths all contribute to a receiver that sounds quiet and natural compared with many older transceivers.
If you want to extract the best possible performance from your FTX1 try these steps:
- Make sure IPO is selected for a clean front end on HF.
- Use preamps only where you really need them, typically on 12m, 10m and VHF/UHF bands, or when using a short antenna.
- Switch in the attenuator on crowded lower bands like 80m and 40m to prevent overload and reduce the noise floor.
- Experiment with RF gain to reduce the background noise while keeping the desired signals readable.
- Try switching AGC off for a more natural listening experience and a lower apparent noise floor between signals, taking care to reduce audio gain before you start.
- Use the SDR filtering to narrow the passband by a few hundred hertz on SSB when needed to cut noise without harming intelligibility.
These changes will help you hear the FTX1 at its best. With modern SDR receiver architectures you can achieve a near ideal signal path. There will never be a perfect receiver, but the FTX1 and the FT-710 have pushed receiver performance a long way forward in a practical and affordable package.
Thank you for reading. I hope these explanations and practical tips help you to enjoy your FTX1 even more and to get the quietest, cleanest receive performance possible.
"The receiver section is absolutely amazing and it's really cutting edge stuff."
For more information please visit our online store or alternatively contact us and our team will be happy to assist you.