MAGNUM S-9....OUTPUT MOSFET REPLACEMENT...IRF520N

Another MAGNUM S9 which needs new MOSFET outputs, what a surprise! - these newer transceivers with there ERF2030/IRF520 type outputs really go through them which is probably why many of the CB retailers here in the UK have stopped selling these types of radios!... mind you it does not help that owners of these radios keep turning up the power which contributes to output failure.

Category:

Sports

Tags:

• MAGNUM
• S9
• REPAIR

[SouthCarolina116]

Are the IRF520N mosfets any more robust than the ERF2030 mosfets? I have a blue faced Magnum 257 with the ERF2030s and they blew over nothing even with a low SWR.

[weazle66]

@SouthCarolina116 The problem is that there not RF linear devices and are also very static sensitive and can fail easily.

Some say the 520's can take more abuse but there basically the same device.

[24nov67]

My SS3900 uses these irf520s for both output and rf final driver, you say that they were'nt designed for this purpose (to amplify rf) & as 2sc 1969's &2312's are now all but obsolete are there other devices on the market that can be used in place of the mosfets should they ever fail?

[weazle66]

@24nov67 The IRF520's were not designed as linear RF devices bit will amplify RF, The SS3900 uses the same board as the older models but with the output stage modified to accept the MOSFET's as the 1969/2312's were made obsolete by Mitsubishi.

As the output circuit has been changed specifically for the IRF520/ERF2030 transistors you can not really use another device without circuit modification, as the IRF520's are so cheap anyway replacing them is not really an issue if they fail.

[bluejay148]

why can i audio in am whistling shows fault reading

[weazle66]

Whistling to show peaks, i also could see the meter peak when talking.

[terry77877]

mmmmmmmm

[julietcharlieen1]

I just bought 4 of these finals from you on eBay to go in my S9. it's been off air for 6 months at least and finally got found to making the effort about fixing it

[26TM240]

@NowLifeStarts SS-158 Drifter LMFAO i wouldn't touch a crappy Superstar if it was free and came with flowers... We had one in our workshop and couldn't get it to stay on frequency for more than 20 minutes... SuperFail 158...

[manonhill12]

stuff like this always happen to the crazy expert that is doing the so call peak and tweak

[teamfab]

I cant believe it.. a Magnum when on SSB thats almost on frequency!!!!

[NowLifeStarts]

Do not buy these shitty Magnum radios. Buy a SS-158edx instead.

[JettaJ1]

my s9 has 3 2030s i see 65w on am with a 10w dead key. low power i have a 4w dead key swing to 25w i lowered my dk and swing for my amp. only thing i dislike about mosfet this radio is the damn deadkey when the radio is cold startup the deadkey raises. not very stable at all!!!