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Hi Paul, Thanks for the quick reply!! Yours has the BRN and BRN/BLK the reverse of mine(which is wrong!) I was to the point where I was going to open up my working L-4PS to see how it was wired!! Not

Many thanks Jim, I'll look in eBay to get some beads. 73 de Raoul CE3RY

Here's what I have in my files: -- 73, Paul K6PO

I will have another look later, as I have to open up a rig. The two HPF spares that I have did not have beads on the ALC board. I have found examples with beads on both ends of the red wire between

Wow! A lot of good information, thanks! Jim, I'll reply based on your comments: * "Did you also add a ground strap at the other corner where there is an empty screw hole in the inner chassis wall?"

Well, I went back to the MAMA manual (Both the PDF and the DJVU files) It appears I dod not get the above picture from BAMA asw the schematic there has no identification of the primary winging

Thanks Jim I don't have a TR7 manual, but that is a different part number. Bill N0CU [email protected]> wrote:

Howdy all, This question has probably been asked before,? but I am having a little trouble with the plate transformer primary connection identification. I have 2 plate transformers removed from

I have no idea. You would have to check the manual. It is a 3N204 in the TR7. "Bill Leonard N0CU via groups.io" <billincolo73@...> wrote: -- 73 -Jim NU0C

Is this FET the same device that is used in the R4-C mixer circuit? Bill N0CU [email protected]> wrote:

The following files and folders have been uploaded to the Files area of the [email protected] group. * /[drakelist] Oscillation in TR7 (2nd Mixer FET).pdf (

The following files and folders have been uploaded to the Files area of the [email protected] group. * /Drake TR7 Up Converter Alignment.pdf (

Another change to the 2nd mixer that was not included in the VE7PS list is a shield over L701. Most boards will have a shield over L703. Very early boards will have neither. Also notice that early

Here is another somewhat obscure point regarding the 2nd Mixer. I also saw it inked in to a paper service manual that I came across so I know there are at least two people have done this. :)

Bob, Thank you for keeping us informed of your progress and success. 73, Evan, K9SQG

When it was serviced, did they replace the can capacitor? I have had similar failures due to this cap opening. Steve Wedge, W1ES/4 Time flies like an arrow. Fruit flies like a banana. Sent from

The oem Drake plate block caps in the L7 are failure prone. They went cheap, and used a pair of disc ceramic caps.? When they fail, they typ fail shorted.... which will take out the .82 ohm HV fuse.

Did you also add a ground strap at the other corner where there is an empty screw hole in the inner chassis wall? 73 -Jim NU0C "Raoul Meunier via groups.io" <rmeunier@...> wrote:

Thanks Jim, Kam and Gary for your comments and pictures, very explanatory!?I definitely need to do more work after looking at those ferrite beads over several wires. Today I added a ground strap to

Collins had the same issues originating from the use of tube socket mounting screws as grounds for critical RF circuits, especially in KWM-2’s and S Lines. A lot of problems were repaired by simply