Possibly faulty amp?

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funkmaster
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Possibly faulty amp?

Post by funkmaster » 15 Apr 2019, 21:47

I am having a bit of trouble with my linear and not sure if I am doing something wrong. It is 200w FM and 400w on SSB.

On FM I get around 160w which is what I would expect however on SSB I also get just 160w .

I have tried different variations of power into it (upto the maximum) buy no change

Any ideas ?

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Black Spirit
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Re: Possibly faulty amp?

Post by Black Spirit » 16 Apr 2019, 07:09

What amp is it ? Very rare will an amp do what the factory specs state and are a bit over exaggerated.

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prettypolly
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Re: Possibly faulty amp?

Post by prettypolly » 16 Apr 2019, 07:53

Even my kl 505 v only does 300 ssb on no 6

Blackolive
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Re: Possibly faulty amp?

Post by Blackolive » 16 Apr 2019, 08:15

SSB rating is "peak envelope power". you need a special metre to read this. a normal meter on whistle up or speech will show about the same reading as on FM

funkmaster
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Re: Possibly faulty amp?

Post by funkmaster » 16 Apr 2019, 11:35

It's an old Silver Eagle 777. Thanks Blackolive , I guess that may mean it's ok then as I am using a standard Zetagi 1kw power meter which reads just over 160w on FM. I realise advertised specs are well over the top, I just wanted to double check it's not faulty

funkmaster
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Re: Possibly faulty amp?

Post by funkmaster » 16 Apr 2019, 15:31

Just a thought but this amp has 2.5mm power cable as looks like it's been rewired at some point, do you think it could do with something thicker?

Blackolive
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Re: Possibly faulty amp?

Post by Blackolive » 17 Apr 2019, 08:45

Ive had a look at the spec.
http://www.cbradio.nl/Silver_Eagle/777.htm


current draw is 22 amps.
2.5mm is a bit under rated, and to help prevent volt drops, I'd be inclined to use some of this, 3mm²

http://www.vehicle-wiring-products.eu/p ... sq-44-0-30

( Im about to orser some for a couple of amps Im rebuilding )

It also looks to have a couple of glass fuses on the PCB.

cant see whether they are 20 or 25mm, but I would see what rating they are and fit 25 amp fuses. Also make sure the fuseholders are nice and tight.

Finally, if you are using it on FM, dont be greedy with output power, give it an easier time and it will last a lot longer

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andrew013
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Re: Possibly faulty amp?

Post by andrew013 » 17 Apr 2019, 09:10

as said above when amps say 200 fm / 400 ssb or what ever output power just expect to get around 85 % of the fm power , , linear manufactures use this duel output power spec just to get people to buy them oh look it will do 600 on ssb , so thats 300 then , you dont see hf rigs go 100 fm 200 ssb they just say it tx`s 100 watts all mode
on air,tyne&wear,northumberland,durham,holy island,eu120+eu124 and anywhere from gateshead/north wales
scrap uk 40 give cbers L/M/Hcalling on 27.355/555 usb qsy 27.015 lsb/410 usb cb radio is for life not just for profits
i do cb radio not 11mtres,countrys worked 2015 with imax 2000 72

funkmaster
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Re: Possibly faulty amp?

Post by funkmaster » 18 Apr 2019, 21:24

Thanks for the replies chaps, much appreciated

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