HFU HF Underground
General Category => General Radio Discussion => Topic started by: Matt285 on February 07, 2020, 2355 UTC
-
I posted this here because I feel like the Pirate radio section is for reception info. I know this question applies to various forms of transmission, but I was wondering what the factor is when running a pirate station and choosing between AM vs SSB? I know some of this would be based on the transmitter being used. When transmitting on this type of platform and you have the capability for both modes, what goes into the decision? Thanks
-
This topic might be appropriate for the Technical -> Equipment forum, but I'll leave it here for now.
Historically, pirate radio operations on HF were almost always on AM up until the early to mid-1990's. This can probably be attributed to the large amount of very cheap, used tube-type equipment that was easy to find at hamfests. As time went on, SSB began to become quite popular as the availability and ease of keeping old AM gear on the air became a problem. But AM was always a little easier on the ear.
Now we are kind back in a transition period where it's fairly easy to get on the air with a good sounding AM signal due to the availability of "SDR" transceivers. Flex and ANAN transceivers sound really good on AM. And there are other AM options, like individuals who build/sell custom transmitters for AM. You can find them here if you look.
The mode you choose to broadcast in, then, is a factor of personal preference, technical capability, and finances. I think most pirate HF listeners are versatile enough to treat both modes equivalently. Me, I like a good sounding AM signal, but I'll listen to any pirate regardless of mode. In recent times there have been some pirates who can do sideband REALLY well - Mix comes to mind.
If you are looking to broadcast, I'd go with "run what you brung" and then backfill/improvise/tweak as you get feedback from listeners and figure out what you are comfortable with.
-
Quality, power, conditions...in that order. Although this has been covered many times in all kinds of places I can't locate at the moment, my personal thoughts on it haven't changed. My focus has always been on quality first and foremost. With modern SDR based rigs it is very possible to run wideband SSB, but gear like this isn't reliable enough for my kind of field use. AM transmitters as of late have become quite easy to build up to stupid power levels...SSB not so much.
Content plays into this as well. If you are running mostly spoken word or talk material, SSB is fine. Music is much better on AM, as getting the tuning correct for music takes a lot of practice and a good ear. Most of the recording I got during my SSB days were quite a bit off frequency, and thus didn't sound very good.
+-RH
-
SSB is a tool of the Devil. It's not called "Satan's Sideband" without good reasons.
-
Construction wise A.M. is now very simple with highly efficient 'Class E' and PWM modulators (class D). No need for huge modulation transformers etc.
SSB whilst being far more efficient signal wise has to use 'Linear' amplification which is not as efficient as class E. However NXP have developed the BLF188XR which make generating 1Kw or so of SSB a fairly simple affair.
That's it from a 'Technial' perspective!
Str.