PA3BFM reviews the Yaesu FT-920
by Frank van Dijk, PA3BFM, Six News February 1998
With the FT-920 Yaesu, one of the worlds leading equipment manufacters, has finally recognized that a serious HF transceiver should have 50 MHz capability. In this article, I hope to show you what the FT-920 is like. As space is limited, I will focus on the FT-920s receiver section and some of its general operating characteristics.This articles function is a quick scan of the FT-920, aimed at the experienced DXer and by no means intends to cover all of this transceivers features. By popular request, I have also included a few notes comparing the FT-920 and the Icom IC-756 as these products are the worlds first quality shortwave transceivers to include 50 MHz. Each offers different advantages to the modern operator. (Franks review of the IC-756 was published in Six News 54, pp22-27.)
Many thanks indeed to Mr. Hans Schaart of Schaart Communications of Katwijk, the Netherlands, for giving me an FT-920 on loan.
Beauty is in the eye of the beholder
When I saw the FT-920 for the first time, I was truly impressed by its beautiful appearance. Although its just cosmetics, the FT-920 really stands out from its more spartan-looking competitors.
Before we take a look at the receivers performance, I would like to summarize some of the FT-920s specifications. The receiving frequency range is 100 kHz - 30 MHz and 48 - 56 MHz (I dont know whether the 30 - 48 MHz range is accessible after a modification).
Except on FM, the receiver uses double conversion, the first IF being 68,985 MHz and the second IF 8.215 MHz, followed by audio level post-AGC digital signal processing (DSP).
On FM a third IF is used at 455 kHz. A 500 Hz CW filter is available as an option at the 2nd IF. For the bands above 21 MHz, a preamp can be inserted to crank up sensitivity. For improved strong signal handling, mainly on the bands below 14 MHz, a three stage attenuator is available.
The FT-920 transmitter operates on the amateur bands six - 160 metres at a maximum of 100 watts output. The FT-920 needs an external power supply. Current drain at 13.5 V DC is 22A. The built in automatic antenna tuner works on all bands.
Receiving with the FT-920
I spent quite some time playing around with the receiver during the CQ WW CW contest and the week preceding it. In order to get an idea of its strong signal handling capability, I concentrated on 7 MHz where I have a sloping dipole available, suspended at 21 metres. This is high enough to guarantee a low level of locally produced noise and to let me hear what is really there.Well, to be honest, it was hard to find any 3rd order mixing products at all! The only noticable effect of the extremely potent stations in the nearby 41 metre broadcast band was that the receiver sometimes appeared to be a little nervous. The insertion of a mere 6dB of front-end attenuation completely solved this. When a receiver can cope with the bombardment of RF on 7 MHz, it will most likely also withstand it on 50 MHz, basically a much less harsh RF environment.
As far as sensitivity on 50 MHz is concerned, I could hear the LX0SIX beacon with it, which is about the sensitivity benchmark in this neck of the woods.
SSB reception is excellent. The bandpass width of the standard IF SSB filter is just right and the sound quality produced by the receivers AF section is superb, both on an external speaker and on my Heil ProSet.
On CW, with the 500 Hz CW IF filter switched in, selectivity was good enough to copy signals in most situations. Only when it got really crowded could a 250 Hz IF filter have helped in further reducing the QRM from adjacent stations. Its a pity that the 500 Hz CW filter had noticable passband leakage (blow by). This problem could be caused by the lay out of the pcb near the filter, the signal levels present there, or the filter itself.
The DSP
Happy owner Kees, PE1MCD, with his FT-920On SSB, the DSP was quite helpful in carving out the weaker stations. The DSP controls are designed so that you can independently manipulate the upper and the lower audio passband. By turning the inner and the outer DSP controls together, you can also shift a passband across a signal. This worked quite satisfactorily. On CW, I found the DSP filter a bit woolly, by which I mean that it was possible to narrow the passband down to a certain level but after that it lost its sharpness.
I will not elaborate on my objections to post-AGC DSP. In crowded situations the infamous AGC pumping could indeed be noted, but for the occasional CW operator this is no problem. With a DSP like this, that occasional CW user can even do without an additional narrow IF filter.
Im sorry to say that I couldnt find any positive effects of the DSP noise reduction, to the contrary it tended to smother marginal signals.
What I liked about the FT-920:
The received frequency remains unchanged when switching between modes:
What happens to the received frequency when you switch to another mode? Nothing at all! You can joggle between the various modes and both the actual frequency and the displayed frequency remain exactly the same. Great! This has been very well thought out by the Yaesu design people. I wonder why other manufacturers dont implement it. When you have a transceiver that is less than perfect in this respect, but that does have CW and CW-reverse capability, you should at least try to get accustomed to receiving CW on the same sideband as SSB.
CW SPOT:
If you dont use CW, skip this section. Still here? OK, what is CW SPOT? This feature allows you to position your CW signal exactly where you want it. How? When you push the CW SPOT button, youre hearing a tone that represents the way the DX station would receive your own signal. I say TONE because on CW SPOT actually generates an audio signal that simulates a beat note. By listening to this tone and manually adjusting your transmit frequency, you can now place your CW signal right where (you hope) the DX station is listening, in a pile up for instance. Why is this important? Well, if you want to break a pile up other than on sheer power, the thing to do is to exactly match (or better: mirror) the operating style of the DX station.
This CW SPOT is a very clever feature. Not unique, because the old Drake C-line that I used during my 160 days also had it. On the Drake C-line the SPOT function used a very small amount of real RF to create a true beat note. Obviously, CW SPOT only works on CW.
The manual:
Consulting the manual of your transceiver may help you to hear more DX. Dont try to operate the FT-920 without studying it. The FT-920 manual is quite a book, nearly 100 pages. It has been written in excellent English, clearly by a native English speaker who is an active amateur himself. This made it easy to understand the manual, without having to further interpret the text. The manual sometimes goes beyond explaining the mere functions and also shows the practial use of that function. If the FT-920 would be your first HF transceiver, or if you have been away from ham radio for a long time, this will be very helpful. Unfortunately, the manual only rarely uses cross references and the schematics and block diagrams have been printed far too small.
The display:
On contemporary radios all information about the equipments settings is relayed to the operator by means of the display. This means you have be able to read whats on the display under all lighting conditions and from a variety of angles. The FT-920s display meets these criteria and not only that, the display makes operating the 920 a pleasure. The only criticism is that information about secondary functions seems to pop up in random places somewhere on the long display, making it harder to recognise the status of the transceiver at a glance.
The Digital Voice Recorder:
This used to be a rather expensive accessory, but now you get it for free on the FT-920. You can use it to record not only your own voice but also to record the receivers audio. So now you can check if you really made that subtle QSO in a pile up, or if you just thought you did.
What I didnt like about the FT-920:
The CW speed control knob is too tiny, making it hard to adjust your sending speed. You have to push two buttons each time you transmit the content of a CW memory. In my eyes, this is an unforgivable error.
The VFO B tuning knob acts as clarifier. This is a bit confusing when youre not used to it.
The 8 MHz IF thats used in the FT-920 is not found on other Yaesu rigs, so the standard range of optional IF filters is not available.
The so-called Dual Watch. Unfortunately you cannot receive on two frequencies with it, it acts more like a priority scan function. All users of the FT-920 I queried admitted they had never used Dual Watch.
The FT-920 versus the IC-756
A slight disappointment for those who had expected to read here which rig came out best. Having used the two in parallel for some time, I was able to make a few specific comparisons but making a final judgement between rig A and rig B is a strictly individual decision, depending on ones activity profile.OK, here we go and remember, these are only general conclusions:
On SSB reception, the 920 is more pleasant to use than the 756. This is because the 920 AF sound quality exceeds that of the 756 and the latter has a 2,8 kHz SSB filter which actually is a little bit wide. The 920 has more DSP functions available on SSB. On reception of weak SSB signals however, both rigs performed equally well.
Clearly, the 920 was not designed with the CW operator in mind, because the 756 is the winner on CW reception. Hardly any filter leakage, more filters are available and the narrow DSP filter is more effective.
The strong signal handling capability of the two rigs is equally excellent. I had the feeling the LX0SIX beacon was just a little stronger on the 756.
So on receive, in general I dare say the rigs performed equally well. After having said that, all that remains is the traditional higher retail pricing of ICOM equipment, including the 756. For this you get a Dual Watch function and a Band Scope that really work, plus a highly functional dot matrix display.
Conclusion
If you regard the FT-920 as an attempt to design and market a quality transceiver, on which the traditional 455 kHz IF has been replaced by DSP, there is no doubt this attempt is a major success! Except maybe for the absolute CW nerd, the FT-920 guarantees the owner with many years of operating pleasure on HF and 50 MHz. I can certainly recommend the FT-920 to you!Thanks department
Thanks to PE1MCD for providing the photos; thanks to PA0ERA and PA0JMH for evaluating the FT-920 with me, and thanks to Hans Schaart for providing the test model.Further reading
- Yaesu FT-920 product review, N1RL; October 1997 QST.
- Praxistest Yaesu FT-920, DK8OK; Funk October 1997 (German language).
- FT-920 HF and 6 m transceiver reviewed, G4HCL; Ham Radio Today, August 1997.
- FT-920 review, G3SJX; Radcom August 1997.
You can also order an Expanded Product Review Report from the ARRL Technical Department.
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