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Johnson Viking 4740

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Sheriff Bart
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Johnson Viking 4740

Post by Sheriff Bart » Friday, 18 September 2009, 12:52 PM

Hi guys,
Can someone give me the parameters to do peak and tune ? I cannot find any info on this old beast.


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Night Crawler
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Re: Johnson Viking 4740

Post by Night Crawler » Friday, 18 September 2009, 13:49 PM

AM Power L8 L9 L10

Modulation AMC R212 or cut R203

SSB ALC R726

The PLL can also be modified for extra frequencies.

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Foxhunter
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Re: Johnson Viking 4740

Post by Foxhunter » Friday, 18 September 2009, 13:58 PM

I almost bought one of these 4740 radios a few weeks ago while raiding a guys shack for some other goodies. I wish I'd gotten it and a Drake L4 he had, but I'm getting really low on finances. I do have the 4740's tiny little brother the 4140.

I can feel for 'ya there isn't a whole lot out there on this radio but let me at least get you something and get you started. Maybe bump your post along a little too. You've wrote me in enough of my threads right?


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Johnson Viking 4740 Tune Up:
{ T704-T706 --- R212-AMC --- R736-ALC }
http://www.geocities.com/kb8qfl/adj/j.htm" onclick="window.open(this.href);return false;

Johnson Viking 4740 Tune Up:
Modulation: --- R216 or Cut CR203
AM Power: --- T704 T705 T706
SSB Power: --- R726
http://www.**NON-SPONSOR**.com/mods.htm" onclick="window.open(this.href);return false; (oop I see I can't link this one censored)





Here is a nice little write-up page on the radio describing it's similarity to SBE and Tram
EF Johnson Viking 4740
http://home.ptd.net/~n3cvj/efj4740.htm" onclick="window.open(this.href);return false;



Thought this PLL sheet might be handy. Finding similar or nearly identical radios sometimes to can give you clues where to look on your own rig. Evidently the PLL for the 4740 is shared with these other radios including the Tram D64. Having the numbers might be useful.


CB PLL Modifications List
NDC40013/M58476


Models include:- Craig L131/L231, Johnson Messenger 4730/Viking 4740, NDI PC200/PC201, Tram D64, Pace 1000BC/1000MC/SS-120, SBE Console VI

This chip was designed to replace the MC14526/68 pair.Used in SSB models only.

Modification is done by using an external oscillator to replace the doubled 20 Mhz mixing signal coming from the 10 Mhz reference divider.




Here is a plain but very helpful webpage for adjusting many of the popular older rigs. There is a rather wide screen shot of a tune-up sheet there too and you will need to reduce your screen size or scroll sideways to view it all (I almost missed several columns by almost not noticing). This lists the same tune-ups to the 4740 as the site at the top I linked to.

http://wizard50wy.tripod.com/id9.html" onclick="window.open(this.href);return false;

I Remember


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Sheriff Bart
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Re: Johnson Viking 4740

Post by Sheriff Bart » Saturday, 19 September 2009, 7:14 AM

Thanks Nightcrawler (wassup with your avatar) and Foxhunter..I have enough info now to get busy and get this radio in my rotation. Speak on the fine families


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Night Crawler
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Re: Johnson Viking 4740

Post by Night Crawler » Saturday, 19 September 2009, 10:55 AM

Sheriff Bart wrote:Thanks Nightcrawler (wassup with your avatar)
It disappeared by itself one day and never got around to putting it back.


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443 Arizona
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Re: Johnson Viking 4740

Post by 443 Arizona » Thursday, 29 April 2010, 14:40 PM

hey guys, without getting picky, i see reference to r726 and in another post, r736,,, could this be a clerical error?
i have one of these radios and plan to look into these mods, 73's... this is my first time on this site too, so treat me like a virg for at least the first minute.


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