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Author Topic: MARS THUNDERBIRD MOBILE TRANSMITTER  (Read 8745 times)
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K9EID
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« on: December 23, 2018, 02:09:00 PM »

I have acquired one of the cute little Mars Thunderbird AM Mobile transmitters in 99.9 condition.  Any one have a schematic of connection information?
I will not use the mobile power supply on the rear panel.  I also have the MARS station control console.

Like to hear form anyone that can help with schematics, etc.
Bob Heil, K9EID
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Todd, KA1KAQ
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« Reply #1 on: December 23, 2018, 02:20:35 PM »


Nice find, Bob. They also had a number of accessories including SWR bridge and I almost think there was a matching amp.

There's a fellow out on the left coast who collects this stuff and may be a good bet for documentation. His name is Larry Rau aka Capt. Larry. His W6 call escapes me at the moment, though I probably have his email address somewhere. Years back I used to send the stuff his way whenever I came across it in my travels.

Good luck with it and please post some photos of it when you get a chance. Not a lot of those little rigs left out there.
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known as The Voice of Vermont in a previous life
WD8BIL
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« Reply #2 on: December 23, 2018, 05:44:18 PM »

Is this the guy Todd?

W6WUH
LAWRENCE D RAU
16615 COLEMAN VALLEY RD
OCCIDENTAL, CA 95465

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WA4WAX
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« Reply #3 on: December 23, 2018, 08:07:18 PM »

Dear Bob:

See page 41.  Too bad they did not include a schematic.

Matt
WA4WAX

http://www.electronicsandbooks.com/eab3/manual/Magazine/Q/QST%20US/196003%20[188].pdf
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K9EID
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« Reply #4 on: December 23, 2018, 08:40:31 PM »

Thank you for this Matt, however I can not get it to open.... good ole. 404. Error.

I will keep digging and hope we can rustle up a schematic or more information regarding the LARS THUNDERBIRD.

Appreciate your time and talent.

Bob Heil, K9EID

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WA4WAX
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« Reply #5 on: December 23, 2018, 08:57:35 PM »

http://www.electronicsandbooks.com/eab3/manual/Magazine/Q/QST%20US/196003%20[188].pdf

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WA4WAX
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« Reply #6 on: December 23, 2018, 08:58:17 PM »

Bob:

March 1960

http://www.electronicsandbooks.com/eab3/manual/index.php?dir=Magazine/Q/QST+US/
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K9EID
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« Reply #7 on: December 23, 2018, 10:28:53 PM »

Thanks for your help.   I was not able to get back to March 1960 QST.  All in the post you sent were late years.

Appreciate you help.   Keep digging to find info and schematic for the little jewel.

THanks
BOB HEIL, K9EID
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WA4WAX
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« Reply #8 on: December 24, 2018, 06:19:57 PM »

Bob:

Try again.

It goes all the way back to 1916!

Start at the very top, and look carefully on the left.
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K9EID
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« Reply #9 on: December 24, 2018, 06:30:58 PM »

Thanks so much.   Got it all and I certainly appreciate your time.   Anyone have any other information about this unique little jewel, please feel free to send along.   

Bob Heil, K9EID
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w4bfs
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« Reply #10 on: December 24, 2018, 07:16:58 PM »

this is what I really like  ...  wa4wax received a lot of help and now he is giving a lot of help ... brings a tear to my eye ....well done
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Beefus

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It would from many blunders free us.         Robert Burns
K9EID
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« Reply #11 on: December 24, 2018, 07:51:49 PM »

Thanks, guys.  This is what Amateur Radio is all about.  Have to feel sorry for those that have not discovered, lived or began with boat anchors ....   I appreciate all of the help - and I will do doubt need it to get this little Mars dude up along side the EiCO stations.....
Merry Christmas to all !
Bob Heil, K9EID
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K9EID
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« Reply #12 on: December 28, 2018, 09:08:45 PM »


I just received a beautiful clean schematic of the MARS M T  75 that friend Gene W4IQN has so gracious drawn.  He has been doing all of the glorious drawings for the Pine Board Project we have been building on Ham Nation this year.
If you desire a copy of the schematic and nice parts list, please send me an E Mail at K9EID@arrl.net

I am excited to get the MT 75 on the air.   Looked into it last evening to discover 'someone' had been inside and lifted the cathode of the 12AU7 from ground and connected that pin to the PTT pin of the microphone jack.   I figure this is 'his' way of keying the transmitter.  I quickly returned it to the original position.... GROUND.  Everything else looks pristine and untouched.   Any one have information of any kind for me, please feel free to send along to K9EID@ARRL.net. I appreciate your help.

Bob Heil
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K9EID
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« Reply #13 on: December 28, 2018, 09:14:05 PM »

/Users/bobheil/Desktop/MARS draft copy.pdf

Bob Heil, K9EID
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K9EID
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« Reply #14 on: December 29, 2018, 01:14:09 PM »


Making headway on figuring the little jewel out.  I have a big issue.... I need the microphone connector to fit this jewel.  Yes, I probably have 5,000 mic connectors in our warehouse but they are all Foster connector and not even close.

Appreciate help on the mic connector as I do want to use the original.   


Sure appreciate all of the help you guys are giving me.   

BOB K9EID

* MARS draft.pdf (148.18 KB - downloaded 232 times.)
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K9EID
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« Reply #15 on: January 07, 2019, 12:34:53 PM »

I have th microphone connector!   Had to 'build it' but it is good and makes good solid connection.  I Used one of the HRIL Stealth microphone connector bodies and an insert from an old connector of. years god by.   It all fits and looks to be the answer

Thanks to all of you that have searching for the original. 

Now on to connecting some filament and B+ to see if the little jewel is going to work.  If not - we'll "fix it".

Thanks, again for all of your help.... this is what makes Amateur Radio the best hobby ever.
Bob Heil, K9EID


* IMG_5925.JPG (1318.14 KB, 3264x2448 - viewed 491 times.)
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WD5JKO
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« Reply #16 on: January 07, 2019, 02:02:07 PM »

Hi Bob,

   Nice little transmitter you have there. Take a look at this link:

https://w5hro.com/threads/mars-thunderbird-mobile-transmitter.1/

Looks like the right microphone was chosen for the job!  Tongue

Actually, this rig needs a DC biased carbon mic.

Jim
Wd5JKO
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Patrick J. / KD5OEI
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« Reply #17 on: January 17, 2019, 10:06:20 PM »

Glad you were able to make the connector.
I found these Amphenol today while cleaning up the lab, but not sure they are the same as yours, I didn't see a pciture to go by.


* IMG_0695.JPG (359.81 KB, 1100x1030 - viewed 414 times.)
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K9EID
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« Reply #18 on: January 18, 2019, 12:36:07 PM »

Thanks to everyone that has been searching for the original microphone connector roe the MARS MT 75.   I finally -woke up - and discovered that our 'Stealth' microphone connecter threads were deep enough to match perfectly.  All I had to do was fit a 4 pin female socket into our 'stealth' and everything works well.   The situation is the threads of the MARS are very 'thin'.   Most all connectors do not have enough thread on the barrel to tighten .... exactly WHY I designed the 8 pin Stealth as all of the new radios really need a larger threaded barrel.  It all works well now, so thanks so much to everyone for the help.   

I have the little jewel on the air, driving it with one of my small mixers at line level out and one of our PR 77D large diaphragm dynamics.   Wonderful experience with this little jewel.  Appreciate everyone's help.
Bob Heil, K9EID


* MARS Heil mic connector.JPG (1318.14 KB, 3264x2448 - viewed 422 times.)

* MARS MT 75 chassis.jpg (30.39 KB, 400x300 - viewed 461 times.)

* MARS MT 75.jpg (19.7 KB, 400x295 - viewed 460 times.)
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K9EID
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« Reply #19 on: January 18, 2019, 12:45:29 PM »

Last but certainly not least, Here is a copy of the newly drawn schematic from Gene W4IQN who did all of the beautiful drawings for the entire Pine Board Project.https://heilsound.com/amateur-radio-post/the-pine-board-project/


* MARS draft.pdf (148.18 KB - downloaded 222 times.)
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