Complete novice needs advice.

It was the 25watt rig i was getting at.
That power would smoke a 50watt burner.
I think 4 or 5watt's was about it on FM.

It was a Cobra 148 gtl dx, with all sort of mods on it, 
Alen you are pretty clued up on electronic stuff, I just wondered if you have heard of anyone modding a power supply, 
I bought a Mercury 15 amp regulated supply, reviews on this were pretty good, except for the noisy fan.
It is annoying and on constant, the first day I opened it up and put a cut out switch on the back,
" I took the switch from the under cupboard lights in the kitchen, while the wife wasn't looking.
Now I have a plan, to buy a silent running fan, drill holes in the top of the case of the supply unit,and mount it , then connect a thermistor to the heat sink, with the appropriate resistor ,transistor and led.
It might look crazy, but it should then only turn the fan on when it gets hot.
I just do not want a fan running constant, when on standby, 
I know the saying "if it aint broke"  I have bodged lots of stuff its in my blood.

Why not just replace the fan with a silent one.

Hi frank133, sorry for the late reply but busy with life! Thanks for the intro & good luck to you too i need all the help i can get. Bob. 

Hi all, finally got my antenna sorted out last weekend after much up & down a ladder & taking the whole thing down to get to the whip. Took 4 goes but got the antenna tuned to the FM UK band & managed an SWR of between 1.2 & 1.6 across the 40 channels. 
I'm not sure how to go about tuning to Euro & SSB as i don't really want to have to take the whole thing down again & start from scratch. There must be an easier way. The only thing i can think of is to put up another antenna & tune it & then just switch cables at the back of the radio, unless anyone knows different. Always keen to learn!
Should be transmitting this weekend as unable to do much in the week at the moment. 
Cheers, Bob. 

Hi Bob,

Good to hear you getting on.

You've done well with your SWR so far, (can be a right PITA!), and would think you're all but there.
If a SWR of 1.2 was at channel 1 of the UK frequencies you should be good to go, it should be around that figure on Euro frequencies on channel 40 and maybe creep up as you go to Euro channel 1.

Just to help out....

A SWR of 1 is all but impossible as you always have losses, (including any meter that indicates as such!) So don't go aiming for that 'penultimate' reading just as low as you can go.

A SWR of 1.2 means you're actually operating at 99.2% efficiency!

At 1.6 you're still running at 94.7% efficiency.

In fact you're still at 90.4% efficiency at a SWR of 1.9 which explains why a lot of radio operators are happy with less than 2.
(Most don't worry until it raises over 3 or 75% efficiency as that points to problems.)


Well mate, roll on the weekend when you get to try out some serious transmitting!
I hope it all goes well for you.


All the best,
Victor

Also don't worry trying to SWR on SSB it can't be done

Hi Victor, once again thanks for the reply, good to know i'm doing something right! On Euro FM channel 40's SWR is 3.1 & channel 1 is 3.3 so don't know what's going on there. I'm going to stick to UK FM for now just to get into the swing of things & if i need to, when the weather gets better, i can put up a second antenna & tune it to Euro.
Thanks as well Nubster, it's all a learning curve & i am slowly learning thanks to you guys!
Cheers, Bob

No worries Bob.

It sounds like the antenna is still set too short mate, you'll have to extend that whip out further. 
I presume the SWR reading you gave was 1.2 on UK channel 40 and 1.6 on UK channel 1?

Do your best to get the SWR as low as you can on either UK channel 1 or Euro channel 40 to be nearer the band spread mark of that antenna. No need for an additional antenna it should cover both the CB bands on the one.

If the whip is as far out as it can be and only low SWR at UK channel 40 then you might have the 10m version of that antenna or the wrong whip?!?   
Worth checking your order receipt just in case.

Leave it until the better weather though, at least for now you know you're safe transmitting on UK 40 and can at least listen on Euro. 


It's all fun isn't it?


All the best,
Victor

Hi all, well so far absolutely nothing to report or any contacts at all on UKFM. Should i abandon it & climb up the ladder again, take down the antenna & re-tune it to Euro FM? Or is it worth persevering as i am? Don't have a problem keeping the antenna as it is on UK & then buying another one for Euro, just want to know if UK's worth it.
Any advice greatly appreciated as usual. Cheers, Bob.

Try the Euro FM as you are don't think the SWR will be to high.
It is very quiet at the moment so don't give up it will get better but when is the big question.

Hi Victor, sorry didn't see your reply. I had to reduce the length of the whip to get the SWR to the right range for UKFM, several goes to get it right, but had to reduce the length each time. Now the EuroFM is 3+ over all the channels. Pretty sure it's the right whip as per the instructions, i.e. the longer whip 11m & the short one 10m. Put the long one in to the mark indicated & then had to reduce to get decent SWR on UK. Don't know what's the best course of action, but i'll carry on regardless! 
Thanks as well to Alan pilot but the SWR is too high on Euro, i'll keep listening for now!
Cheers again guys. Bob.

Aerial must have limited band width then.

Hi 53 Prefect & thanks for the info. Think i'll wait for the better weather to arrive before i do anything else with the antenna. Cheers, Bob.

Hah!  I don't blame you... All was looking good here to do some antenna work. Then the snow came back yesterday!