PRESIDENT JACKSON FINAL OUTPUT REPLACEMENT - MRF477 ELEFLOW

President JACKSON which needs a new final transistor, later version which uses adaptor board and MRF455 to replace MRF477 which was discontinued in the late 1990's.
As usual someone has made a bad job of the repair and so this radio is passed to me which is good as i have a new transistor which will be perfect for this radio.
The new MRF477 from ELEFLOW in the SOT-123 style package with its high gain and emitter ballasting is just the perfect replacement, as i expected a excellent result and with the faulty driver also replaced the perfect combination.

Category:

Science & Technology

Tags:

• PRESIDENT
• JACKSON
• MRF477
• REPLACEMENT
• TEST

[zx636racer]

were could i buy that board any info???

[weazle66]

@zx636racer The board was made by UNIDEN and is now obsolete, i do not know of any sources that may have any.

[scatterpated]

Hopefully you're still checking the comments for this video. I just bought an early 5-band Jackson off eBay. AM power is <3 watts at mid-band into a 1.1:1 SWR. Sideband PEP about 10. Ran into a snag during the transmitter alignment procedure in the service manual. I was able to adjust the driver bias (VR10) for 50mA, but I couldn't get any current reading at all on the final bias (VR9). The radio has the Motorola MRF477 final. Is there a test procedure I can follow posted somewhere?

[weazle66]

@scatterpated Your output is very low, the Jackson should be 10 watts AM/FM and 25 watts PEP on SSB.

Normally if you can't get a bias current reading it could mean the transistor is faulty.

[catalin099]

Hi,

I bought a Jackson I-(1997) from ebay, and it has 2n3632-15 transistor instead of mitsubishi 2sc2166. The final transistor is motorola mrf 455. It is ok ?

[weazle66]

@catalin099 The 2N3632 is a VHF/UHF type transistor and not commonly used in HF applications, the MRF455 was used to replace the MRF477 in later model Jacksons and Lincolns.

[1112223333111]

whats your friend talking on?

Is it a icom 735?

Mines sounds like crap on am too.

[pepsiholic2008]

Nice video :)

That sounds like Charlie Chum Chum who you are talking to ;)

[mrhighlander2003]

hi. this pcb can be made at home using any pcb desing software or draw the board to sketch it on a copper clad. there are pcb kits ready and aviable on the internet.

[Atilanos]

Will be possible to modify a President Jack? It has only one 2SC2312 and a 2SC2166 driver. If the board is modified and a heatsink is included, would be possible to use a MRF455 instead of the finale transistor 2SC2312?

I think it would be a nice mod for this radio.

Thank you!