I have an elderly Codan 8121 HF radio in my boat that I haven't been able to get any reception from apart from weather broadcasts a couple of times.
From what I understand it has an internal antenna tuning capability which is meant to cause a light to change intensity when in the process of tuning in the antenna. My one doesn't! The indicator light doesn't change at all, regardless of the twisting of all the knobs.
I'm wondering if this means that the tuning is not happening, hence the lack of reception, and is there a way of checking the system.
The antenna is an insulated back stay and the unit is earthed to the steel hull.
Does anyone have any words of wisdom?
Any helpful advice would be greatly appreciated.

I have an 8121hf. I had a few problems with corrosion within the switches so I cleaned them up with a contact cleaner, then lubricated them and the antenna would then tune using the load light. Be sure to depress the mike button or hold down the tune switch whilst adjusting the antenna. There are 3 adjustment controls for the antenna and they all need adjustment when tuning to different frequencies and the power switch should be set to high.
Like Lydia said check out the antenna connections ,antenna cable and grounding plate first, Hf radio can be tuff on the grounding connections and eat them away in the bilge environment.

My set has the frequency crystals for VMC and I receive the VMC as clear as a bell in WA. I really need the VMW frequency to get better use of the radio here in the west.

Not many people listen to HF broadcasts any more. You need a comprehensive operator's licence to use a transceiver.

If you can pick one up for $500 or less and get it working for another $500 or less, you are in the ball park of return on investment.

An HF receiver can get you grib files which are useful.

With one caveat, hang in there with the 8121 as they are very reliable and had a production from 1969 into the early 1980s.
they are a crystal set which is the caveat so getting replacement crystals is near impossible.
hence small freq changes are a problem but the most common Freq have not changed so still fine for weather and distress and 2524.

Anyone with a web browser that can run flash can read the handbook online for free:

www.amc.edu.au/industry/omc/handbooks-and-revision-questions

I just wanted to note for anyone interested in the license cost: If you sit the exam (at a current cost of $83 + the cost of a passport photo) and pass, then they post you a perpetual LROCP (or SROCP if you sit the VHF only exam) license.

The VHF transceiver is licensed under a class apparatus license, so there is no ongoing cost to own a VHF radio.

The ACMA want an initial license fee for a HF apparatus license plus ongoing fees. The ACMA kindly provide a 64 page document that describes how to calculate the issue charge + tax + GST and the renewal/installment charge + tax + GST, it is the Apparatus licence fee schedule on this page:

www.acma.gov.au/theACMA/About/Making-payments/Apparatus-licence-fees/apparatus-licence-fees-acma

Around mid 2015 the marine radio certificates were renamed:
MROVCP -> SROCP
MROCP -> LROCP
to "align the naming of Australian certificates with the common world practice". "The new terminonology will more clearly reflect the nature and limitations of these internationally recognised certificates and their equivalency with overseas certificates." (section 1.8 of the Marin Radio Operators Handbook).

So they are just renamed, the marine radio certificates under the old names are still valid.

Having to go and sit the exam is a croc, and probably the main reason only about the estimated <20% of users/boaters actually bother to go to the effort to hold a marine radio licence. If the exam was a simple online affair, I suspect many more would do it and we would hear much better terminology/phraseology over the radio.

First of all thanks to everyone for their replies, and to Lydia and Jolene thanks for your positive thoughts on the 8121, the radio was in the boat when I bought it but there was no antenna and it was not wired to the power supply. There is a brochure with it but not a lot of helpfull info. A couple of years ago I fitted a new insulated backstay and new cable to the radio so I hope that should eliminate any connection worries. I have had the on/off switch replaced at a local radio repair shop and they said that it was working (maybe they meant that the switch was working) anyway I'm determined to have it operational even if it means studying for licence.
When tuning a channel, if I hold the mike switch down or the tune switch on, the indicator light is cut out completely. Is this normal?
I'm situated on the mid north coast of NSW.
The radio has the following channels 2182, 2436, 2524, 4125 and 4134.3 /4428.7 share the one setting.
Thanks again in anticipation.