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Author Topic: Kerri's Xmas Present  (Read 15505 times)
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WA3VJB
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« on: January 02, 2011, 08:31:48 PM »

Got to work the "Christmas present" Kerri KC2UFU put on the air last week.

New Year's resolution:  Hope to hear her on, a lot !

Check these out:


* KC2UFU-e1.mp3 (738.86 KB - downloaded 532 times.)
* UFU-3.mp3 (1266.12 KB - downloaded 364 times.)
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Mike/W8BAC
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« Reply #1 on: January 02, 2011, 09:50:01 PM »

I'm looking forward to getting home and tuning Kerri in. I talked to her and Ken separately a few weeks ago. Kerri told me about the Christmas Present and I have to say I admire Ken's craftsmanship and determination. What I really want to see are some more pictures!

Mike
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WA3VJB
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« Reply #2 on: January 03, 2011, 11:20:59 AM »

Hey Mike, Happy New Year to you !
Missed running across you over Christmas week as I burned vacation time.

We should do a "couples" night.  You and yours, Frank & Carol,  TimTron & Marce, me and mine, Kerri & Ken, whoever else.

The guys could be the board ops, the women could be the "talent," and I think it would sound great !

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The Slab Bacon
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« Reply #3 on: January 03, 2011, 11:25:23 AM »

now that could be interesting. (or we could all be in deep szht when they get done with us)  Grin  Grin

Hell, she doesnt need me to be board op, she has her own call..................
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WA3VJB
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« Reply #4 on: January 03, 2011, 11:41:37 AM »

Well Frank I loved Carol's contribution the other night when you were going on about your 69 Coronet in the driveway.

You had just said how many years you've had it, and she says

POOR THING

because we all know that's the original air in those tires and not much left at that

Y'all need to swap chairs every so often, so YOU can make the wisecracks and she can tell stories on you.


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flintstone mop
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« Reply #5 on: January 03, 2011, 04:37:12 PM »

IF the ladies had their way on couple's night we might have to buy new finals for the TX. Hours and Hours of talk power

fred
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« Reply #6 on: January 05, 2011, 06:50:09 AM »

Got to work the "Christmas present" Kerri KC2UFU put on the air last week.

New Year's resolution:  Hope to hear her on, a lot !

Check these out:



Hmmm....  Kerri's highly modulated signal (with positive peaks well in excess of 100%) shows something interesting in the receiver.  The actual signal doesn't have clipping distortion on it, but there is clipping evident in the recording.

I have heard other R390s with this as well.  I was using an R390 over at another ham's house, and Brent came on - the received signal was distorted and I know Brent doesn't have distortion like this.  His signal is also heavily modulated in the positive direction.  Nick KG2IR also reports this on my signal when he's using an R390.

I don't know anything about the R390 detector, but many [most] detectors I've heard in their stock form exhibit this anomaly.  Have no idea if they all do this, either.

Anyway, thought I'd mention it.  I found when I corrected the problem in receivers I've used, my receiving and listening experience improved greatly, and in general most signals sounded better to a greater or lesser degree, depending.

Regards,

Steve
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WA1GFZ
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« Reply #7 on: January 05, 2011, 08:46:02 AM »

Where can I see a picture of the rig?
Sounds great. No distortion issues at gfz
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« Reply #8 on: January 05, 2011, 10:06:31 AM »

Where can I see a picture of the rig?
Sounds great. No distortion issues at gfz

You probably have a good detector in your receiver  Cheesy  Ken is going to take some pictures of the rig and send them.  I have some pictures of the RF deck, but they are not real good pictures.  He's going to send some of the modulator/power supply and better pics of the RF amp for posting !

It's an older design - a 5 MOSFET per module, 2 module RF amplifier with -eeegads- analog drive, and a class H modulator using 12 (I think) MOSFETs.  Essentially Bob K1KBW's first rig duplicated.
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WA3VJB
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« Reply #9 on: January 05, 2011, 11:49:49 AM »

Quote
It's an older design



Enjoyed that !  
They're all older designs if you're building on Sokol's 1975 work.
Might even be deemed vintage radio !

The receive detector on the R390A does pick up some audible distortion when the transmitter is running reduced carrier (relative to the sideband envelope), somewhere around 130% positive is where I can start to hear it.  

Do you know whether the "older" design runs asymmetrically ?


I see your reference to it now, Steve, yes, that's the problem.
A more balanced transmitted signal does not do this.
Have you thought about a re-design to repair the issue ?

huh-HA !
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steve_qix
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« Reply #10 on: January 05, 2011, 01:44:45 PM »

Quote
It's an older design



Enjoyed that !  
They're all older designs if you're building on Sokol's 1975 work.
Might even be deemed vintage radio !

The receive detector on the R390A does pick up some audible distortion when the transmitter is running reduced carrier (relative to the sideband envelope), somewhere around 130% positive is where I can start to hear it.  

Do you know whether the "older" design runs asymmetrically ?


I see your reference to it now, Steve, yes, that's the problem.
A more balanced transmitted signal does not do this.
Have you thought about a re-design to repair the issue ?

huh-HA !

Yes,older - what does that mean  Wink

I suppose, older for my published designs!  The first class H modulator went public on or around 2000, and the 2nd release quickly followed in around 2001.  This is the one that's the most popular in the field (for analog modulators) right now.  Was trying to get away from Analog, but PWM seems to mistify many folks, while the analog modulator doesn't seem to.

There's just a lot of heat involved with analog, and the power supply requirements are MUCH greater for the same power.  Everything is just bigger with analog. 

A 1Kw (transmitter carrier power) pulse width modulator uses just 5 MOSFETs, and fits on a very modest heat sink.  The power supply has to put out about 8 amps at carrier (at 130V) and a maximum of about 12 amps under sine wave modulation.  Must less with voice.  The modulator is approximately 95% efficient.

The same 1kW, if implemented in analog (class H) would require a 55 to 60 volt 26 amp power supply for the CARRIER, and then another 130V supply with at least twice the current capability (around 50 amps peak) for the positive peak MOSFETs.  The modulator would require approximately 36 MOSFETs (18 in each bank) to give a sufficient safety factor for dissipation and current overload capability.  The modulator is around 75% efficient (at carrier), but that's still around 400 watts of heat and that's alot!  Under modulation, the modulator efficiency is not as high because the peak MOSFETs are essentially operating in class A, so quite a bit more heat is produced (hence the large number of MOSFETs needed).

But, they are all capable of highly asymmetrical modulation because that's the way the voice is (most of the time), and the system just reproduces this without any waveform modification or distortion.
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W1UJR
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« Reply #11 on: January 05, 2011, 01:59:00 PM »

I was working on the radio bench, on a solid state rig - Sad, during the maiden voyage of that TX, heard Bob KBW helping them get it dialed in.

First, its always great to hear a friendly YL or XYL voice on the air, especially one running a home brew rig.
Second, I must say that it sounds strapping, great audio, great signal up to Maine.
Think they live in NJ, not sure of the power output, but as loud as Bob was down in CT.

Wonderful Christmas present - there may be something to those Class E rigs.  Wink

Does anyone have any photos up yet?
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« Reply #12 on: January 05, 2011, 07:41:29 PM »

That thing is impressive. No denying that!
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W2PFY
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« Reply #13 on: January 05, 2011, 10:37:57 PM »

I have heard just about all the E guys, not Kerri so far on my R-390A at camp and I have never heard any distortion on the signals. Yes I do have good ears and a very good speaker that made by Bozak  from the 1960's. I don't need an AF amp, the 1/2 watt from the 390A will drive the speaker to high volume.
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WA3VJB
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« Reply #14 on: January 06, 2011, 10:38:14 AM »

Yeah, Terry, as long as they're not hitting the audio too hard, most of the receivers out here will be able to do just fine. Even on the recordings above that Steve listened to, there are only a few excursions where audible grit showed up, and always when the carrier was so reduced in proportion to the sideband energy.  One solution is to restore some of that missing carrier level by turning on the BFO, but that adds its own problems.

I just think it's great that Kerri, who has a warm voice and is good to talk with, now has Tall Ship status as a result of her husband Ken's craftsmanship.  It's a credit to him for successfully building a nice-sounding transmitter like that, and a credit to her for spending as much time as she does being on the air with us !

Always a pleasure.

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WD8BIL
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« Reply #15 on: January 06, 2011, 11:11:26 AM »

Quote
....and a credit to her for spending as much time as she does being on the air with us !

Her boys love it too! I heard them raiding the fridge last night while Kerry and I were in QSO!
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KC2UFU
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« Reply #16 on: January 08, 2011, 11:31:16 PM »

Here is a few quick pics....don't mind the crappy resolution.

Pictured here is:  1. It's Alive(Sexy...isn't it)
                        2. Inside of the Class H Modulator
                        3. Bottom of modulator (Transformer,heatsink,fans)


* E Rig Posting Pics 043.jpg (58.32 KB, 480x640 - viewed 622 times.)

* E Rig Posting Pics 010.jpg (59.84 KB, 640x480 - viewed 628 times.)

* E Rig Posting Pics 018.jpg (58.54 KB, 640x480 - viewed 614 times.)
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KC2UFU
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« Reply #17 on: January 08, 2011, 11:36:52 PM »

Few More pics:  1. Dead bugged modulator board
                      2. RF Deck
                      3. RF Deck
                       


* E Rig Posting Pics 016.jpg (58.81 KB, 640x480 - viewed 592 times.)

* E Rig Posting Pics 023.jpg (60.93 KB, 640x480 - viewed 591 times.)

* E Rig Posting Pics 024.jpg (60.38 KB, 640x480 - viewed 588 times.)
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KC2UFU
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« Reply #18 on: January 08, 2011, 11:40:07 PM »

...And more pics...(are you guys getting tired of them yet?)

These are all of the 80 meter RF Deck


* E Rig Posting Pics 026.jpg (60.45 KB, 640x480 - viewed 605 times.)

* E Rig Posting Pics 028.jpg (61.25 KB, 640x480 - viewed 587 times.)

* E Rig Posting Pics 029.jpg (59.94 KB, 640x480 - viewed 647 times.)
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« Reply #19 on: January 09, 2011, 09:32:31 AM »

: )


* acmeLogo1.gif (116.25 KB, 628x588 - viewed 554 times.)
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Mike/W8BAC
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« Reply #20 on: January 09, 2011, 09:58:56 AM »

Kerri and Ken,

Great looking rig and it sounds very nice as well. Had a good time Friday night. I don't know how you built that thing without clip leads. I guess a 10:1 scope probe can replace 10 or more clip leads? If you can please post a better front view.

Mike
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WA3VJB
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« Reply #21 on: January 09, 2011, 10:56:27 AM »


Nice job, Ken !

Looks like you were loyal to Bob/KBW's attention to good construction quality as well as patterning the basic design.

Kerri, you've heard the sound files I hope ?   That's only one reason we like hearing you on ...

; )



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K5IIA
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« Reply #22 on: January 09, 2011, 11:14:31 AM »

Thanks for posting the pictures. Great job on the transmitter!
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KC2UFU
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« Reply #23 on: January 09, 2011, 11:29:45 AM »

Kerri and Ken,

Great looking rig and it sounds very nice as well. Had a good time Friday night. I don't know how you built that thing without clip leads. I guess a 10:1 scope probe can replace 10 or more clip leads? If you can please post a better front view.

Mike

Thanks Mike, the pictures are not what they should be....I need to use a better resolution camera...but you get the gist of things....I'll take better pictures of the front today and get them posted.

As for the project itself, you can tell it's not quite finished yet(note the uncut zip tie in the modulator). Zip ties are ken's signature, I've been running my race car for 5 years with the nitrous oxide lines zip tied together in my trunk!(hence, dave's acme sign)
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steve_qix
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« Reply #24 on: January 09, 2011, 12:27:46 PM »

Kerri and Ken,

Great looking rig and it sounds very nice as well. Had a good time Friday night. I don't know how you built that thing without clip leads. I guess a 10:1 scope probe can replace 10 or more clip leads? If you can please post a better front view.

Mike

Thanks Mike, the pictures are not what they should be....I need to use a better resolution camera...but you get the gist of things....I'll take better pictures of the front today and get them posted.

As for the project itself, you can tell it's not quite finished yet(note the uncut zip tie in the modulator). Zip ties are ken's signature, I've been running my race car for 5 years with the nitrous oxide lines zip tied together in my trunk!(hence, dave's acme sign)

Zip ties?  That's DEFINITELIY the sign of a finished project in my shack.  Heck, if there are less than 5 clip leads in the thing it's generally considered done around here!

Certainly is a nice job and of course sounds good.  Considering this is a first project of this type - it's remarkable how smoothly everything went.
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