Yaesu FT3DE & Icom 703 resistance to desense?

Does anyone have any practical experience of using these rigs on 2m FM from “challenging” SOTA summits where de-sense from other transmitters is an issue?

I’m considering a fairly serious upgrade to my radio equipment and I want to know how others have faired with these two radios.

I suspect that (like most modern handhelds) the Yaesu FT3DE may struggle without a bandpass filter in the antenna line?

I love the idea of using the APRS for spotting. I also really like the idea of the bluetooth option, allowing the radio to stay in my backpack (where it stays dry) & using a bluetooth headset/handset. Does anybody else do this?

I currently use an old Yaesu VX-8E which is pretty rubbish as far as de-sense from other nearby transmitters is concerned. It is however good for APRS. Having to use the external mic (which has the GPS built into it & in my opinion sounds absolutely terrible) is a complete pain.

There is a bluetooth module available for my VX-8E (approx £120). I suppose could just upgrade that & make do but I like the idea that everything is built into the FT3DE. I’m not sure if it really makes sense to pay for the upgrade to my VX-8E.

As for the Icom 705, I’m guessing that this will have better filtering & be a little more resistant to adjacent transmitters?

The 705 also has the bluetooth built in. I really like the single USB cable interface for digital modes (I also want to run FT8 from a few summits).

I currently use an old Icom 703 for HF but figured that the 705 will basically do everything from 160m-70cm & is smaller (& probably lighter) than the 703.

I think that FT3DE would be good for spotting via APRS & for lightweight VHF only activations (probably with the requirement for a bandpass filter on some summits).

I’ve also heard some people say that the audio from the FT3DE is pretty poor (especially on FM which is what I would predominantly use it for).

Your thoughts & experiences with these radios please?

Hi James.

This has come up a few times. Best to look at measurements I think, removing the many variables found in the field. Razvan’s thread is a good one:

Commenting only on the FT3…

Yes, the FT3 is not impervious to de-sense and other issues. As with practically any other handheld it is likely worth investing in additional filtering for 2m. I am very happy with the one from SOTA Beams.

Audio - I have received good reports of audio. I use both the internal microphone and a hand mic. The former is better than the latter. On receive the quality is fine but a little quieter than I’d like. Typically I plug it into my 2.4GHz TX to my hearing aids though and bypass the loudspeaker.

I tried the bluetooth. It is very limited in the profiles it supports. It’s basically just the oldest one for hands-free devices - I don’t remember the official name - and not those for fancy stereo headsets, &c. I also found that when the radio is squelched it still sends audio on the BT with a low hiss. I don’t understand why that should be so! There were also issues with it disconnecting (to save power) by chance just at the point the radio was about to receive something. I keep meaning to try it again though, as it would be useful.

My biggest complaint is the screen, which is very hard to read in strong light. It is also fragile compared with your typical summit rocks. I prefer an FT1X on a longer hike in case I take a tumble. The GPS seems just as good.

Composing an APRS message on the FT3 is somewhat less of a nightmare than it is on the FT1X! (crib sheet absolutely required)

Thanks Simon.

That’s a very interesting article. I’ve been through it & compared all of my handhelds.

As I suspected, my Yaesu VX-8E didn’t fair that well. My Icom IC-E92D did marginally better but they both have wide band receivers (the phrase “wide open barn doors” springs to mind).

The FT3DE isn’t on there but assuming similar performance to it’s predecessor the FT2DR, it looks like it will be on a par with my Icom (which although not great, it does ok for the most part). It does struggle on some summits.

My old Kenwood TH-K2 faired quite well (it is a mono-band radio, so I guess that would be expected). I might have to obtain a replacement battery & resurrect that!

The big surprise was how well the Wouxun KG-UVD1P did, supposedly outperforming all of my other handhelds. I have to confess that I have never taken it to a summit so I can’t really comment but I wouldn’t have expected a cheap Chinese radio to do so well. I’m left asking myself “are you sure about that?”

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I can’t add a lot because although I have an IC 705 I haven’t yet tried it on FM from a summit. What I do know is the adjustable filters it has work very well on HF. For example, listening to CW it is possible to discriminate down to a single transmission and exclude or at least significantly reduce other very close signals. I don’t see why this shouldn’t work the same on FM.

However, if you mostly want to use FM then the 705 might be considered overkill.

The audio from the handheld microphone/speaker isn’t great but you can disconnect the speaker lead leaving only the microphone and it then switches to the chassis mounted speaker which is much better.

Connecting to a PC is very simple although when operating from external power at 10W there can be RF issues on some bands but on 5W these seem to disappear. Winding the USB lead around a ferrite toroid and/or adding ferrite beads helps too. These issues are on HF only in my experience. On 2m I can use 10W without taking any preventative measures.

Thanks John. That’s very helpful.

I agree. Although I also activate on 40m & 20m, so really want a “shack in the box”.

Currently I’m carrying an Icom 703 which works very well (it’s a great radio) but it is bulky. The 703 is HF only so I have to take a second radio for 2m FM.

The 703 also requires an external battery whereas the 705 has an internal battery (albeit that you can only use 5 watts on the internal battery, so I would still have to carry an external battery if I want the full 10 watts).

My thoughts with the 705 is that I can consolidate 2m FM & HF into one radio.

I’ll probably still take a handheld to some summits (if only for the APRS capability + maybe a backup) but I figured that the 705 almost certainly has much better filtering & therefore better resistance to de-sense on difficult summits.

It will also be smaller (& probably lighter) than the 703.

I guess to some degree I’m trying to reduce the amount of bulky equipment & weight that I have to carry.

In my late 30’s, I wouldn’t consider myself to be particularly old & frail but I do get mild back pain (the remanence of an old injury) so I have to be a little bit careful what I try to carry.

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I’ve had the FT3D for several months. SOTA activations with a Signal Stuff “Signal Stick” antenna have been great. I have the same opinion of the speaker: meh. Usually I end up turning up the volume to get decent audio clarity. APRS is great but be prepared for an undergrad class in APRS system architecture and some practice. And with GPS on for APRS position beaconing, the battery drain goes up a bunch. One, maybe two SOTA activations on a recharge so I run with GPS off unless I’m activating.

The FT3D has lived up to expectations and does a lot for such a little unit. I would recommend it.

Awesome, thanks for the feedback.

Just a quick update in case anyone was wondering…I ordered myself an Icom 705 last night. Can’t wait for it to arrive.

I probably will eventually get the FT3DE as well, but that will have to wait until I’ve saved up some more money!

I’m fairly sure Paul W6PNG/M0SNA has a VX8 and said that you can tame many of the overload issues with careful use of the attenuator function. Worth experimenting with next time you can. Sure, you may no longer receive the weaker stations but you may at least be able to work more of the stronger stations.

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I got an early VX8 (not D) on and used it for 6, 2 & 70 and it worked great, I had no issues, I even made a few 6m FM contacts. I never really had desense. I did sell it a few years ago and then bought an FT3D.

The FT3D I have used for successful activations and in the car, no real issues with audio quality, but I have found Band A suffers from more desense than Band B.

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