Do you really need a Linear Amplifier?

 Ever since I came back to HF in January 2024, my friends have been advising me to go for a linear amplifier. In VU land, the General Class licence which I have, has permission for 400 W power, though my radio can only give me 100 W. Almost every other operator who I hear on 40m has a linear amplifier. Then what is it that prevents me from going for a linear RF amplifier to boost my signals?

When I came on air with my FT-710 radio with full power of 100 W, there were many on 40m who asked me whether I was using a QRP radio! The reason was simple, I was new to commercial radios and did not know how to adjust the radio. I had kept mic gain low and the processor level also low and I was scared of using the built-in automatic antenna tuner because of the rattling noise it makes! When I increased both mic gain and processor level and started using the auto-tuner, others started hearing me better.

Then that was not all. My antennas were highly compromised due to space limitations. I started experimenting with different orientations for my 40m antenna as well as different types of mounting. In yester years I had the luxury of tall coconut trees on which I could tie a horizontal dipole. But now I can hardly squeeze an inverted V dipole. Initially I was using a galvanized iron pipe as the central mast, which I changed to a slightly longer telescopic fibre glasspole.

After several experiments I could find a rather optimal location for my 40m inverted V dipole and people started giving me 5,9+10 dB reports! I switched over from the thinner HLF 200 cable to thicker RG 213 cable with lesser loss. I added a 1:1 current balun bought from a local ham at the feed point as well. Now at least during good band conditions, some have started asking me whether I am using a linear amplifier. That is my journey from 'QRP' to 'QRO', all with the same radio and same output.

With the current setup, I do not think I have much for scope for improving my signals unless I go for a beam or a linear amplifier as the inverted V dipole has been somewhat optimized to the maximum for my QTH. Beam is out of question, except possibly for 6m or 10m as I have very little space on my terrace which is mostly slope roof with tiles. The most important reason why I am not going for a linear amplifier now is the high level of noise in my radio most of the time. S9 noise level is the norm on 40 and 20m! With such high noise levels, I struggle to hear DX stations most of time. If I am able to hear a station, well, most of the time I am able to work them as well, though reports are not that encouraging!

So next I have to experiment with loop antennas or separate RX antenna to reduce the noise levels. Otherwise, even if a linear amplifier improves my signal report one or two S points at the other end, I will miss out many stations who are likely to call me back. Another reason which prevents me from a buying an expensive linear amplifier is the need for an additional external antenna tuner, which will add on to the budget. The built-in automatic antenna tuner in my FT-710 will be disabled if I connect a linear amplifier.

With all the constraints I have for antenna mounting, working without an antenna tuner is out of question. May be when Solar Cycle 25 starts going down and my signals fade off, I may be forced to buy a linear amplifier and external antenna tuner, to remain on air! Or should I go for a compromised 80m antenna and try my luck on lower band, the propagation on which will improve as the Solar Cycle ebbs?