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> Mfj 9040 Advice, Getting back in
cgriggs
Posted: March 09, 2017 02:09 am
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Can you believe the idiot writes poetry? LOL
Anominuo ... unaminimeuo ... unknown
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cgriggs
Posted: March 12, 2017 12:11 am
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Just told via internet that KD1JV Tri-Bander Transceiver shipped. 1 to 3 Days expected. I'll have 40, 30 and 15 Meters. ... Now to wait ....
Charlie
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cgriggs
Posted: March 14, 2017 01:06 am
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The package came at 3:00 today. I have the resistors mounted on the main board. The conden ... capacitors go on tomorrow. (I'm taking my time on it!!)

Gotta admit, my heart was in my throat when I opened the box. It's been a long time and I've never put a "kit" together. It's always been buying the parts as needed and laying out, etching, drilling, etc my own boards.

So far no missing parts. LOL

Once again I'm breathing hard with high expectations. (Been a long time for that too. LOL)

Charlie
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kellys_eye
Posted: March 14, 2017 10:01 am
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I admire your self-control laugh.gif

I'd have sat and soldered until it was finished (or I was finished laugh.gif ) given I'm the kind that can't wait......

Also interested to hear how you think of its performance. My own simple receiver is the exact same circuit but on perf board - busy making the input filers at the moment - and I've modified it for variable bandwidth control.

Please let us know thumbsup.gif


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cgriggs
Posted: March 14, 2017 02:14 pm
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Assuming I am able, in my old age, to finish this, would you share your modification? (Same circuit and all.) Maybe I'll have recharged my youthful challenges to keep going by then.

And 25 years ago I'd be going at 20 wpm or so with the finished product by now, but that's 25 years ago. And I'd be sorely in need of a few hours of sleep, I might add, but with old age comes patience and perseverance. ... well, theoretically, at least! LOL

I had a terrible time soldering those teeny holes until I remembered an old forgotten trick of filing a small angular flat on the pencil's tip. What a difference! I was beginning to think that I'd have to buy a new Weller pencil. This one was bought in the 80's. I've got several spare tips and barrels.

I must admit to having a dream or two about the kit last night too. sigh. LOL

"Back in the saddle" Charlie
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kellys_eye
Posted: March 14, 2017 07:39 pm
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Not sure about filing the tip of the iron - many are 'plated' these days to prevent corrosion from the solder flux so be aware that the tip may only last as long as you need to complete the circuit!

The filter modification: referring to the schematic on page 23 of the manual, capacitors C4, C5 and C9 on the crystal filter are replaced with varactor diodes, the cathodes of which go to the crystals and also to individual 100k resistors, the tops of which are joined together and the control voltage applied (via an op-amp rail-to-rail buffer).

I've yet to trial my filter version but do know it requires careful matching of the crystals (mine has FIVE in the filter and I presume your four have already been appropriately matched?) and I also purchased FIFTY varactors to get four with (reasonably) matched V/C curves.

If I can get the filter parameters in a graphical form I'll repost the details to see whether you think such a mod is worthwhile.

Still not decided whether I'll stick to a fully variable control voltage or just use a switched voltage with appropriate calibration for the bandwidths required (mainly SSB and CW). I'll post up a pic of the receiver board shortly to compare to the pro solution biggrin.gif


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cgriggs
Posted: March 14, 2017 08:10 pm
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Judas Priest! LOL I understand about the first sentence and that's why I mentioned the extra tips, etc.

The rest ... Well, ... I think I'll wait for a lil more experience before I "ride the bus" with your modifications. LOL It's a Steelers football expression from the days "The Bus" played too. He carried the ball across the goal posts, with an ear to ear smile, while 7 or 8 opposing players were holding on, being dragged. (Ya hadda love him!)

Lois is in bed feeling a bit lousy so I'm staying out of the attic, and the kit, until she's feeling better, hopefully later today. Just in case she needs anything. Then the conde ... capacitors get soldered in. (Yeah It is killing me! LOL)

Charlie
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cgriggs
Posted: March 16, 2017 01:03 am
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Capacitors are in. Tomorrow the electrolytics, plus ..? Depends on the time, I guess. I think I'm afraid of finishing it and having no project to work on. (Nursing my beer.) LOL

Feeling great!

Charlie
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cgriggs
Posted: March 17, 2017 01:21 am
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I've got it up to where I'm installing the IC's. Uh ... I'm afraid I'm in the market for an LM358.

Directions said, "Next install the four 8 pin sockets". (Something to that effect.) So I inserted one of them. Then I realized I had inserted an IC. Aarrgghh!! (The wrong one, at that). There were no sockets to insert, but IC's. (I think I better reapply for my novice license!!) It's just plain stupid on my part. Gotta slow down, I guess. I quit for the night. I'll figure out how to get the IC out of there without ruining it, if that's possible, and it probably isn't.

Charlie
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kellys_eye
Posted: March 17, 2017 01:26 am
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A simple solder sucker or some solder braid will get most of the solder off. If it's the LM358 then you could apply heat to ALL the pins at once (it involves increasingly fast movement of the soldering iron between pins!) whilst pulling it with a pair of pliers.

The LM358 is very common and not easily destroyed by heat - you're more likely to pull the pins off it first!



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cgriggs
Posted: March 17, 2017 08:02 am
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I sent for an Ungar IC Extractor at Ebay. Later today I'll get an Ungar Soldering Iron too. Looks like this might be a smart move for this "starting over" old dude! LOL
On Edit: Judas Priest!! Another "old fogie" goof up!! There's a thousand ... (well, almost a thousand) Ungar models!! sigh

When the Extractor comes I'll go to Home Depot and try to match up the threads, if it's possible.

On Edit: Judas Priest! Stung again! The extractor arrived. It grips the ic to pull it loose after applying heat to the other side, unsoldering the legs. ... sigh . Don't get old! LOL Back to the drawing board!
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cgriggs
Posted: March 21, 2017 10:20 pm
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I did the dirty deed! I snipped out the IC and put the right one in. Now I'll wait for my ic order to get here and install the one I ruined. I think this kit may get done before I leave earth. LOL
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kellys_eye
Posted: March 22, 2017 01:56 am
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QUOTE (cgriggs @ March 21, 2017 10:20 pm)
I think this kit may get done before I leave earth. LOL

Wow!

An amateur radio kit builder AND a ticket on Space X (or is it Virgin Galactic?).... ohmy.gif

Retirement certainly does pay laugh.gif


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cgriggs
Posted: March 22, 2017 02:15 am
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(or is it Virgin Galactic?)
Them words ain't in my dickshunarie!
It's not retirement that pays, but a thrifty wife. I miss the gigantic computer, new BMW motorcycle and complete Collins rig I could have had if I had my way financially way back when. LOL
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