Yaesu FTA-450L on outdoor antenna

[Know_More_Lies]

Apologies if this has been covered, but I could not find anything related. I own Uniden SDS100, SDS200 and SR30C as well as a Baofeng BF-F8HP Pro.

Recently, I installed a J-pole antenna 7-feet from the house, which stands 10.5 feet high. Grounded properly to my knowledge. Coax runs through jumper under a closed window into my home through various connections, lightning arrestor and BNC male to my choice scanner. I've been connecting the Baofeng and SR30C to it with few issues. With the added power (I guess), I have to increase the squelch more than just using their regular handheld antennas. Both of them work relatively well. I even tried it on the Uniden SDS100 with decent analog results.

With my excitement, I decided to purchase a dedicated ATC tuned radio. In comes the Yaesu FTA-450L. Great radio, but I cannot connect it to the new antenna, as the hissing just does not go away, even with squelch turned all the way up. This seems to be a more sensitive device that acts different than the rest of my gadgets. Or something.

Is my device defective, or am I missing a setting somewhere to eliminate this issue? I wanted to bring the issue here, before messing with the freshly installed antenna. Thank you!

 

[frazpo]

Status? I'm thinking of purchasing one of these? Did you end up liking it?

 

[rk911]

Status? I'm thinking of purchasing one of these? Did you end up liking it?

Do you NEED a transeiver...are you a pilot?

 

[frazpo]

I was leaning towards a radio that was designed for AM airband. Most canners and such are not specifically designed for that use. If I were to go that route I would just disable PTT. I am not a pilot, just a listener of air band traffic.

 

[chief21]

Is my device defective, or am I missing a setting somewhere to eliminate this issue? I wanted to bring the issue here, before messing with the freshly installed antenna. Thank you!

I found this note on the Yaesu site. It might help with the squelch setting.

Why does my radio always make noise and show the word BUSY on the display?
In most cases it is necessary to adjust the radio’s squelch (SQL) level correctly. 1. Tap and release the SQL button once. 2. (IMMEDIATELY) after releasing the SQL button rotate the lower rotary knob clockwise to increase the SQL level several settings until the noise is gone. 3. If it did not work, make sure immediately after you release the SQL button, to turn the lower knob clockwise. The radio will time out if you wait more than a few seconds.

 

[Scan125]

I have a Yaesu FTA-250L and you can disable PTT

 

[frazpo]

I have a Yaesu FTA-250L and you can disable PTT

Thx for the reply. Not getting a response from OP so,, Are you pleased with the radio?

 

[Scan125]

Yes I am pleased.

One has to remember that these airband transceivers are not scanners. Whilst the FTA-250 has a Scan function it is 3+ times slower than a UBC125XLT (or 125 scanners)

What I like about the FTA-250 (and by extension I guess the 450) is:

1) Being certified it gets all the airband frequencies right and especially the 8.33 one. if you are not familiar with the European 8.33 spacings then when ATC says contact/dial abc.efg that is a reference channel and not always a frequency. The actual frequency used is different. See Scan125 Control Program User Manual as an example.

2) Li-Ion battery and charge station, multiple battery choices available

3) Fully rugged chassis and water proofing

4) Supports those EXPENSIVE pucker aviation headsets should you want that quality

Some negatives compared to a 125 scanner:

1) Speaker audio is not as good
2) It is heavier
3) Dedicated to civil airband only and does not cover military
4) Programming via a PC is limited to Yeasu's own program. No full functional control

Back to basics.

Users of these transceivers are not scanner people. The units are commercial dedicated units that will tune etc to required freqs. and work.

I would expect that for use around airports and air shows the user would do their homework as to what the main freqs. are required. If for no other reason and FTA-250/other scan rates are slow and there is no close call function.

Certainly the dedicate airband transceivers are certified and fit for purpose. But with that comes some limitations for Joe Blogs wanting to just scan the airband.

 

[devicelab]

Some negatives compared to a 125 scanner:

1) Speaker audio is not as good
2) It is heavier
3) Dedicated to civil airband only and does not cover military
4) Programming via a PC is limited to Yeasu's own program. No full functional control

1. 100% agree -- the audio output could be better. There is a DSP Rx Noise Reduction circuit that's interesting but at low settings (4 levels) the audio still sounds digitally distorted. (Especially with weaker stations.)

2. Heavier than... what? It's not that heavy.

4. USB cable is expensive and proprietary. Like he said, the software is pretty limited.

5. No USB charging. You must use stupid charging cradle.

I like it overall -- the white LCD is really nice and good on aging eyes. It also uses a BNC jack which is much more rugged.

IMHO, the best sounding and receiving VHF AIR receiver is a Uniden 325P2/996P2. The lower level Unidens sound pretty good too. (I believe they all use the same receive circuitry.) The audio quality sounds amazing. Scan speed is very fast. RF signal "pull" is really good. Squelch control is also very good. Very few 'cheap' transceivers do VHF AIR that well. (Note the Uniden SDS scanners are good but not as good as the older models, IMHO. A little squelch happy.)

The Uniden AIR service search is already pre-set to 8.33khz which pisses me off. ;o)

 

[frazpo]

Great replies. Thank you very much. For those that have both a Uniden 125 and a airband specific radio (Yaesu), Do you find the sensitivity comparable?

 

[Scan125]

I can't really say as I've not really done a back to back comparison.

You could look at the specs for each in the airband freq range.

 

[devicelab]

Great replies. Thank you very much. For those that have both a Uniden 125 and a airband specific radio (Yaesu), Do you find the sensitivity comparable?

My 325P2 was a tad more sensitive than the FTA250L using an external antenna.

 

[alcahuete]

Great replies. Thank you very much. For those that have both a Uniden 125 and a airband specific radio (Yaesu), Do you find the sensitivity comparable?

Generally speaking, scanners are going to be more sensitive. Airband radios are used either in a close airport environment or where you have altitude.

 

[Scan125]

Generally speaking, scanners are going to be more sensitive. Airband radios are used either in a close airport environment or where you have altitude.

450L
Sensitivity: Better than 0.8 μV (for 6 dB S/N with 1 kHz, 30 % modulation)
Selectivity: >8 kHz/–6 dB
Adjacent CH. Selectivity: <25 kHz/–60 dB

BC125AT
Sensitivity (12dB SINAD) Nominal
(AM) 118.800 MHz 0.4 uV

On uV then the 125 is more sensitive HOWEVER one has to evaluate/take into account the measurement metrics (12dB SINAD verses 6 dB S/N with 1 kHz, 30 % modulation)

I leave that as an exercise for those more familiar with RF measurements.

 

[devicelab]

On uV then the 125 is more sensitive HOWEVER one has to evaluate/take into account the measurement metrics (12dB SINAD verses 6 dB S/N with 1 kHz, 30 % modulation)

I leave that as an exercise for those more familiar with RF measurements.

Yep, and it's not a direct conversion either.

The 0.4uV is pretty good for AM on any receiver.

FWIW, the 325P2 and 996P2 are measured at 0.3uV for VHF AIR AM.

 

[Scan125]

I just had to ask AI.

A receiver with 12 dB SINAD is more sensitive than one with 6 dB S/N under identical test conditions.

Here's why:

📡 Understanding SINAD vs S/N​

• S/N (Signal-to-Noise Ratio) measures the ratio of signal power to noise power. A 6 dB S/N means the signal is just twice the power of the noise.
• SINAD (Signal-to-Noise and Distortion Ratio) includes both noise and distortion in the denominator. A 12 dB SINAD means the signal plus noise plus distortion is 15.8 times greater than the noise plus distortion alone

Sensitivity Thresholds Explained​

Metric	Definition	Typical Use Case	Sensitivity Level
S/N Ratio	Ratio of signal power to noise power only	AM receivers, basic tests	Lower (less sensitive)
SINAD	Ratio of total signal (signal + noise + distortion) to noise + distortion	FM receivers, detailed tests	Higher (more sensitive)

• 6 dB S/N means the signal is twice the noise power.
• 12 dB SINAD means the signal is ~15.8 times the noise + distortion.

🔬 Real-World Sensitivity Comparison​

Under identical test conditions (1 kHz tone, 30% modulation):

• A receiver rated at 12 dB SINAD typically requires less input signal (e.g., 0.25 µV) to produce intelligible audio.
• A receiver rated at 6 dB S/N might need more input signal (e.g., 0.5 µV or higher) to reach the same audio clarity.

This means the 12 dB SINAD receiver is more sensitive, capable of detecting weaker signals with acceptable audio quality.

🧠 Why SINAD Is Preferred​

• SINAD includes distortion, making it a more comprehensive measure of audio quality.
• It's the industry standard for FM receiver sensitivity testing.
• A higher SINAD value indicates better performance at lower signal levels.

If you’re comparing two radios or designing a system, go with the one rated for 12 dB SINAD—it’ll pick up weaker signals more reliably. Want help calculating actual µV sensitivity for a specific receiver or modulation scheme?