618T-3 HF collins aircraft radio, k0ip, collins military radio, 618T-3b, 714e-3, AN/URM-157, MRC-108 jeep, mrc-95, 426T , 488A-2, 490t-1, maintenance manual 618T-3   
Collins 618T-3 Aircraft Radio  -- Ham Radio -- KIP
Something new, the 618T-2 page   A work in progress.

This web's a collection Books, Schematics, useful info. supplied by various 618T users,
When I was building my 618 system I had to search here & there to find information. Somewhat frustrating at times, So I've tried to bring it all together in one place.  once I started then many of you send more documents.
How Good can it get,  hams helping hams.  keep that info coming, ur pictures too.

HELP !!
If you have any updated,  PDF's of books, personal stories,  or have any 618 and related equipment for sale , or
know a source of 618's, parts and pieces and accessories  please send me the info so I can get it on this web.  
my email is k0ip (a) ida.net  call 208 251 6441
 

FYI: There's a Collins 618T  User Group on Yahoo
A place to get answers, stay in touch,  and give help to others. link
This user group will become a great resource when more folks get on line . sign up today.......... 

Fellow Hams, and especially DX visitors to the USA,

Please, BE MY GUEST
If your in the area of Yellowstone National Park. Stop in for a Visit
My home in Pocatello Idaho is on
interstate I-15,  one of the main routes to Yellowstone, Jackson Hole & Grand Teton National Parks.

Stop by for a visit & some local Pocatello flavor.
I would love to meet you. Get out of the car and have a coffee, beer - maybe more ? 
your invited

try to give me a Heads Up -- call or write , if possible..Otherwise just knock on the door.
tnx John
k0ip (A) ida.net  call 208 251 6441

Note, way at the bottom of this page,  there are a few other radio PDF's  !
 

KIP's home page    --    do you have surplus you want to donate ??         Join me on Linkedin search john wilson k0ip

All Email addresses on this web have been change to prevents Robots from harvesting them from this web.  protecting me and you..
Note:  if you see  (a)   in an email address,
you need to change it to a @. and close any spaces, emails have NO spaces.

NOTE: Most Pictures on this page can be ENLARGED by clicking them !

     

 

BACKGROUND STATEMENT..
Warning: I am not trying to tell anyone that I am an expert, I really have little knowledge about the radio's internal circuits, other than what I can learn from reading the instruction books and schematics.

I first saw one of these marvels when I went to a MARS convention in St Louis MO, in the early 60's.  I was still in high school, and a new ham...  The Collins guy had a wire out a window and was dialing in frequencies and talking with Cedar Rapids (?). This freq, then that freq, then another, it was like magic WOW what a radio. 
If  your old enough to remember. I had a 20A using a ARC-5 command set VFO....
I never thought much about  getting 618T on the air, until my friend Math ON8PO convinced me I should do it. So I did, now I have two working units, one being the MRC-95 jeep configuration.  I'm now looking for a 24 volt jeep at a price that doesn't break my bank account or marriage   .. HI HI 

There are 3 versions of this radio,
none of them are very user friendly as far as the power requirements! 
From what I know,  the T3 is the only model that's easy to get  power for,  its mostly brute force 24VDC (see below 24VDC)  and a small amount of 115V/400cycle. However,
I have had letters from folks with large 400cycle motor-generators  powering other 618T versions .
The 400 cycle power is a problem, but nothing that can't be overcome. see below 400Hz
Be careful what you buy, I bought a  516H-1 thinking would make 400 cycles, it doesn't !!

What you need:
A big 28Vdc power supply and a 115Vac 400 Hz supply. the proper control box.
You can use the interconnect diagram (listed to the right) and make a wiring harness.
If I had it to do again, rather than using the URM-157 Test set, 
I would  make a 19" panel with the control head and whatever controls / jacks I needed. Something like this picture would be deluxe !!
This 19" control panel is sure sweet, it looks like a Collins product, I don't have a
part number, but just maybe there are some of these floating around out there in
radio land somewhere ?????  Keep your eyes open at flea markets ..

Picture from VK3XAO
 

 


How about an AIR DROP ??
click to enlarge

     

 Hey Guys,  all these books and manuals were free, but every month I send the
 web host $4.95 to keep this web up on the air.  SORRY,  not free any more ,
 but cheat at $5 for the entire library.  Click here

These are high quality PDF's,   complete manuals, not a page left out. If you've
got a 618T, these are what you need .  you probably don't need the older books, but they are here if you do.  






ARC-105 info page


possible sources of radios, and parts
Fair Radio - Murphy's - BPB  surplus -  for plugs William Perry Company 502-893-872
-- Ebay. -  for plugs  Lasaero UK -


For Sale Area.    & Wanted            for personal sales only

Personal Sales Page
Some of the equipment that is presently be listed on the personal sales page
click the button, for a better description and some pictures.

These listings are free, if you have something for sale, let the webmaster know.

400 hz    POWER SUPPLY INFO

       

For more info about the power
requirements for the 618T-2 Please
see the  618T-2 page ..  the 208V isn't completely clear, it depends where you measure the voltages, ,  read the t2 page.
 

 
Collins 426T-1 400 cycle power supply, this supply is used in the MRC-95 
This is rated at 115Vac Square wave, 400Hz, 630VA 
click here for Schematic

bigger view, Front   Back
EKCO STATIC INVERTER-E182  Click for Schematic







 
I THINK ?? Andy  has TWO LEFT ?? $50  in the UK, phone 019 22 692887
Email: andysavionics(a) hotmail.co.uk

Another Collins inverter, made for
the 618 is the 488A-2


one interesting thing: this supply plugs directly into the 390J-2B rack
(shown below, see racks)

 


also a T-195 Dynamotor will probable work if its all you can find, as might
other dynamotor type devices .

 

this  400 cycles Supply
DOES WORK, in use
its only rated at  150VA ??
$49 at Murphy's
STATIC INVERTER

from a reader of this web page

A source of a 400 cycle power inverter is the PP-2352 that converted 28V DC to 115V 400 cycles.   They were used in the Jeep Tranceivers.

73,  Bob  -  W0RY


And this GREAT 400Hz project
from Takashi JA6ATY
who powers his 618T with a modified
 12 Vdc to 100Vac Car  Inverter.  Link

 
Tested and working !!

 


400 Hz power supply project
that might have enough power to supply  the T-3 radio. it uses a commercial power inverter,
a little construction is needed !!
Take a look at F1FRV web,  download the zip about the power supply, if 200 watts is enough and you can get the proper transformer,
THIS MIGHT BE an easy way to get the 400Hz..
This is worth checking out !!
I recommend going to his web and getting the file
however its here , however if he makes updates my file won't include those.  he also has good info on the 490T-1 Tuner
Thanks F1FRV  --  F1FRV web


24 VDC supply

One possible recommendation:  shop Ebay for a Lambda
LRS-58-28 ..       LRS-58 model..   Shop the "Auction's only", for
better prices..

a note from a 618 owner:  I have this power supply  running at 25
volts, it just sits there quiet as a mouse even in TX Tune mode.  It can
be turned up to almost 27 volts before its internal over-voltage
protection circuit trips.
 

 

 

Control Heads

Control Head, be sure to read  "618T sales".  You can learn a lot about the correct parts and pieces.
There are lots of control heads on Ebay, most are priced "out of sight".  If your in a hurry, buy a good one, otherwise
I say, take your time and keep looking for one at a reasonable price.
This is the 714E-3 Control units, I am not sure how it differs from the C-3940/ARC-94 (to the right) it looks the same on the front .

There appears to be a wide variety of various part nr.
714E-1
714E-2/-2A/-2B/-2C
714E-3/-3B/-3C/-3D/-3F/-3G/-3H
714E-6/-6A/-6B
another slightly interesting item , a test set for these heads
ASI-162  link  on web link  anyone out there have a real picture of this test box ??
Military heads that works  .. click it
There may be more heads that work , however, this is the only ones I know about . 
C-3940/ARC-94
Click Front or Back view ,
_____________________________________
here's a picture of the front and back of the
714E-2.. it has a different connector than the Military units. click pictures to make them bigger.. note lack of CW and Data modes 

  
pictures from K7APO
This is the 714E-6.  It' s for the
618T-3B
Note the 100hz digit

Click   Front  or  Back view, bigger

PLUGS
Getting the plug for the back of the Radio?
When I built my radio setup, I could have purchase the female plug for the back of the radio, but I wanted to sit the
radio in a rack, so I purchased a brand new retro-fit rack 49-T4.  This "retrofit"  trick is used so the
aircraft Weight and Balance doesn't need to be recomputed. and the old aircraft wiring works.
This saves the aircraft owner a lot of money.

the female that mates with the radio,
Cannon DPE-60-335,  a 60 pin connector. some confusion it maybe a DPE-60-33S
the female that mates with the commercial (?)control heads ,    at least the 714E-2 the female that mates with Military control head, Cannon 20-39  (at least that's what mine says) the female that mates with the 426T-1 400Hz supply ,   Cannon DPX-32-02-339

bigger view

Looks like Amphenol  4 S81 ??

bigger view

bigger view

if you have more info about plugs or any of these numbers are found to be incorrect, PLEASE let me know.
note: some of the companies I have listed above, to the right, sell these plugs,  HOWEVER, I think they are thieves, asking $200 or more for a connector !!
if you find the 60 pin connector for $50 to $100 dollars, that's probably fair,  any more and someone is trying to take advantage. If you discover a source that's fair
buy them all,   I bought 7 of these for around $55 each, and sold them on this web for my cost + 10%, , the six were gone within a few months. now I have a free spare for my
next project !.  Note I only have the one.

RACKS  

note: the 618t must be elevated , as forced air escapes from  the bottom of the radio. 

49-T4 Retro fit rack

 

 

This is the 49-T4 Retro fit rack .
Note: the WIDE sides..

the non-retro mount, I think is
5821-00-758-5632   or
554-5375-005

maybe ??  



Also
390J-2B PART 622-1253-001
click the picture to make it bigger
you can see, on the top, a small connector
that mates with the 488a-2 inverter.


TEST SET   Proper name  "" Test Harness, Radio set AN/URM157""

Please NOTE:   These are great to have,  There are several different configurations,   the older units, like the one on the left have a toggle switch and do not work with the 3B model radios,  it works except for the 100 Hz switch doesn't connect through to the radio. The unit on the right has a rotary switch and does include the  connections for the 3B radio (see just below)..  if you get the entire test set, it comes with many cables,  to connect all the 618t parts and pieces together. if you can get the complete TEST HARNESS it's all you need to get on the air . 
AN/URM-157 (Test Harness) 

higher RES view,  Another hi-res view 
note: The URM-157 test set is for all three 618T models, I've heard that selecting the wrong radio might cause smoke ??  Probably nonsense ???  But as with everything, be careful to plug the radio into the correct connector, and select the correct radio & control head before applying power
  (Test Harness) later version TS1949A/ URM-157A  
This unit works with all 618T-x versions including the 3B and its 714E-6 head.
Note: rotary switch in bottom row, it selects the type of control head to be used.
also, the cable is labeled 714E-3/6  so whether this cable works with the E1 or E2
heads  is an unknown .
 
  a bigger view of this picture  ,   front controls close up,   top plugs close up.
Collins MK-722A/URC Test set, it has extenders for the 618 modules..         manual download <--            click me to make me                   -->
heres some pictures    one  two  three  four

 
618T-3B  Late production commercial units   (here's a PDF in German, with block diagrams)
The 618T-3B model does 100hz steps,   It has a different synthesizer.
The 3B was introduced at the end of the 618T's production and was only offered for commercial service. 

Since the 3B radio was never offered to the military, the military AN/URM-157 (Test Harness) is not wired to accommodate 100Hz steps even if you
have the 714E-6 head.  The military test set only test the 714E1, 2, 3  control heads, which are all not wired the same ! make sure to select the proper head.
Please see discussion about various URM-157's just above....

the 618t-3B has  4 extra connections   W on the head  to  20 on the radio ,       X  to 21 ,   (lower case  k ) k to 22,     (lower case j )  j  to  23 .

a 618T-3B it will work using a 714E-3 head, however there are NO connections
for the 100Hz control wires.  If you just let them FLOAT you will be off frequency.
There is a matrix in one of the books showing how the 100hz switch works,  none of the possibilities are all open
I suggest you ground  radio pin 23  and leave 20,21,22 floating,   this sets the 100hz to              

 



(note 1) looking at the interconnect diagram it's a little hard to make out some of the pin numbers  !!
here is a picture of the connector that plugs into the back of the control box as well as a picture showing the radios pin out..
some confusion:  the radio plug pin 24 goes to ' i ' on the control head .
it looks like there are 2 pins that are labeled  number 16 --   NOT so,    16 is to the left of 4  and   18 is to the left of  60, look close
-------------------

Note: the pins on "this diagram" and the pins on the
"interconnect draw" are not in the same ORDER  ,,, Heads up !  don't get confused

OK, Guys,  be careful, some of these designations are confusing,
The  "wire"  designations are not the same as the PINS on the control head connector   !!

here is  3 different views of the same thing
1. <--- to the left,  is the radio connector
2. below is cut from the TM_116625-622-40.pdf
         which contains the complete diagram of the Test set, it is very helpful.
3.  618T-3_interconnect_




click to enlarge the picture       This is the control box connector
for the Military
C-3940/ARC-94

This is the plug that mates with the back of the control head


THIS is the connector for
the (???) commercial 714E-2 control box,
No bigger pins and a completely different metal shell.
click it to make it bigger

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Antenna Tuners ( this is not my topic, however there is a lot of info  on this page)  
  

Other Webs with 618T information
* look down this link for the "618 overview"  http://www.austradesecure.com/radschool/Vol32/Page5.htm  by VK3XAO
                                                                                                                             he has some interesting pictures of a base station rack.
*ARC-105 sales propaganda sheets Plus More    The ARC-105 is a pressurized 618t for use in military aircraft,

* an/mrc-95 forward air control system  http://www.afdasf.org/dasf.html   pictures are listed in sections by the guys that took them, Lots of great pictures
of military life, some of radio jeeps,  but you have to spend a lot of time looking.  it is the source of the information about the MRC-108 Jeep  is  KV4AL 

* PA3GON  several military radios and other information.        http://www.aviation-radio.com/

* Info I found from F6BIR,  its all in French , looks like a home brew 24 V and the 400 hz supply check it out

*. more pictures of the MRC-94,  MRC-108 & MRC-107  link 1  2  3  4

* Interesting site: F1FRV has a LOT of info up about the 490T1 antenna tuner, pictures,  downloads  covering everything about the 490T-1
     and the ARM-109 test set  and info about a 400 hz supply , plus some of his home brew  interface units ,,     LINK
                        Here is a list of non-618t webs about things I find interesting !

*  Heres a web with info about TACAN, IFF transponders, and other vintage avionics  http://members.home.nl/a.k.bouwknegt/index.htm

*  Almost anything military   ON8PO  pictures   http://www.mil-com.be/

* Crypto Museum, This site has a LOT of info, almost too much to digest, very fascinating..   http://www.cryptomuseum.com/ 

* Need info about a lot of military radios,   got something to share with these guys ??   http://radionerds.com/index.php/Main_Page
 
AN/MRC-108
MRC-108  ROMAD , Forward Air Control Jeep,    ANOTHER USE FOR THE 618T click the pictures to make them bigger


More pictures and information about a restored jeep at Wright Patterson National Museum  USAF.
http://www.afdasf.org/mrc108-jeep/mrc-108_jeep.html
NICE


picture by Robert Michael  link go down to 4th DASF  or

 
H.F. Transceiver was a AN/MRC-95 by Collins Model Number 618T3,  718F-1 coffin, 313V-1 control head, 618T-3 radio, 426T-1 power inverter, 460D-1 load coil, 670D-1 tuning coil,  76F-3 speaker.  The HF Antenna was 32 feet tall mounted with a rubber boot for protection to people passing by so that they would not receive RF Burns.  This antenna reduced to 10 sections the width of the jeep. This antenna is a Shakespeare 120 HF Antenna, NSN: 5985-00-846-6442 Military nomenclature: AT-1011/U  and is still available from the factory in South Carolina.   Here's a link to a nice picture and complete radio run down, by Capt. Burt Blatter.   their home page http://www.afdasf.org/

first two pictures are pulled from http://www.qsl.net/ik0moz/admm_intern.htm
more pictures of this configuration at http://www.hypertools.com/pix/pix.html  (down the page )

 


AN/MRC-117

AND NOW here's another one,
the AN/MRC-117 as used with EusCom Command Network in Europe from 1976 to 1984 .

Click,  here's a story ! from an actual user of this system  ,,  WA9Z

here is the only TO I have on the mrc117,
its only covers the mechanical mounting to the truck , no electronics   TM 11-2300-370-15-1.pdf  mostly useless
                                                                 DO YOU HAVE a book ??  please contact me .

Below are some pictures of the control head used in this system ,  more pictures to be added later
click it to make it bigger

a note from WA9Z ,   Is this thing cool or what?!! It mounted on a pedestal between the front and rear seat. There is (was) a removable cover on the control head that had a compartment to store audio accys, pens paper, etc.
There were privacy curtains on the rear windows and between the front and rear seats, and red lights for cab illumination. The operators had a small desk to write, hand microphone, 2 headsets. and a J-38 on a leg iron. As you can imagine, pretty cramped quarters.
Every time a truck deployed the head was installed, and removed when the truck was motor pooled.
As such, I spent most of the time repairing the plugs and sockets.
Haven't seen one of those since 1979. My research leads me to think there was only a few hundred of these ever built for the Pershing II  quick reaction teams.    

click it to make it bigger
 
 





 


IN THE NAVY,,?   do you have any pictures or info about Navy installations..  please send to webmaster,, tnx

HELP SECTION , WE have questions
anyone have any ideas or info,,   these look like the MRC-95 control heads But they are Gray,  indicating NAVY ?? ,
these two boxes  have slight differences.
Do you know what radio this type of control box was used for ???      take a look there is a difference   something to do with filters,
                            313V-2                                     and                                313V-2A
       


Possible First product review ??        Collins Signal Magazine 1960.
click to enlarge .

 

Heres some interesting pictures from the collins PULSE company magazine
some interesting reading,  lots to look at see http://rockwellcollinsmuseum.org/collins_pulse/index_a-z.php#6                   

click to make it bigger, 
1. MRC-108's  all in a row   
 2. 618's on aircraft 3.  see Collins Canada, click to make bigger

 

Hams in Action
Operational 618T's    Hall of Fame !! 
     send me your pictures  and letters                            One left click on most pictures enlarges them !

KIP - The guy that runs this web !!

The 618 is almost visible in the lower bottom , right rack Now for you 618T folks, want to drive the Collins Collectors assoc
net control stations crazy,  most of whom are S-Line appliance operators,  worried about their D104 mike audio...
check into their 20 meter Sunday net with your airline quality audio..  
OK, to be fair, some of them are interested in your strange radio,
but most just think your crazy..  give it a try.. want to gang up on them,  email me your intention and I will meet you on the net ..
I seldom check in. I live in 7 land and by the time they get to me
I'm asleep at the switch. 
and the entire rest of the country has switched Off their s-lines

ON8PO - shown with antenna tuner , home constructed box for
control head and mike and earphone jacks , in a nice transportable display
http://mil-com.be/
JA6ATY
PA1TN

One left click on most pictures enlarges them !
PE1RKS
On the right a 618t that I have build into a case so I could take it with me at field days, 400Hz is generated by the black box inside the case on the right.
On the left you see a MRC-95 that is based on the 618t with the 426t 400Hz inverter.


 
Some detail of the homebrew transportable 618t



  Front of the AN/MRC-95


Internals of the AN/MRC-95

 
 

 WA9URJ

Here is a picture of my test set-up.

I am using a 40 Amp Lambda switching supply for the main 28 volt dc source. The 400Hz inverter is driven by a separate smaller linear supply. I built a panel to hold the control head and other switches and jacks. I have ordered .050 aluminum to make side panels and will eventually make a mount to hold the radio. Here is a picture of the test set up, all mounted on a cart for easy access in the shop.

This is really a great radio and meets the requirement that "real radios have motors".

Many thanks for  all your assistance. My next step is to get the operational level to the point where I can check into the local 40 meter AM net

73's Geo.

 
some comments from Leighton GW3FSP::::: Hi John
Just thought I would let you know the 618t is not dead here in the UK !.

I worked for British Airways until I retired 2 years ago, about 2 years before then I was given a 618t complete with all the mounting cradles, cabling,
control heads, 180r tuner and control system, spares and all the test equipment ( extender units etc ) when BA no longer had any 618t sets in their fleet,
these were fitted to the early 747 ' Classic ' or 747 - 100 a/c and of course the Concorde aircraft, it was originally fitted with the 3 phase 400hz 115
volt ht supply, however I managed to pick up one of the 28 volt supplies from Ebay, ( The A8 module, )

The radio I have will tune to 100hz, so I had to add the extra control wires from the mounting frame to the control head, to get the tuning to work down
to 100hz, I also had to modify the power supply wiring on the mounting frame to allow the use of the A8 power supply and also fit the extra wiring inside
the 618t for the 28volt dc supply, I was also lucky to ' acquire ' a 7amp inverter supply unit from the same source, this is an ELGAR inverter supply unit
which supplies ac from 10 hz up to 1000hz at 7 amps. this I use to supply the 400hz 115 volt supply to the 618t.

I then bought a 42 amp 28vdc switch mode power supply from Ebay which is used  to float an ex aircraft nickel-cadnium 28v battery
( again from BA ) when the radio is in use, it takes a good 38 amps so I'm told when on TX.

And after squeezing the whole lot under my shack bench - it works !, and I have to say it works very well!, rx is very quiet with almost
no internal noise, the noises thing with the radio is the little cooling fan mounted in the front panel for internal cooling which revs up when on tx.
and howls away merrily, it really warms the shack after running the set for about an hour, on ssb I get excellent reports of speech quality using
one of the Seinhauser aircraft headsets I also ' acquired ' with a little whine audible from the 28 volt inverter supply on tx audio, apart from that
I've had no adverse reports .
Hope you are enjoying your hobby, I know I am. 73's Leighton Davies GW3FSP        ps I'm in QRZ.com
 
some comments from Bob  K8RJ about his radio ::::Just stumbled across your very interesting page on one of my most favorite
radios. Lots of super info. 
I am Bob K8RJ, started as K9ITS in 1957 in Chicago , spent 18 years out in Orange County California and now live in Michigan's UP.
My first 618T-3 was one that I obtained in a government auction back in about 1967. At the time it was just a black box on a pallet full of
other surplus stuff. Back then when I had the need for manuals I could go to the Great Lakes Training Center library as a civilian. Lots of things
have changed since then, this is no longer possible. Anyway. all I knew about it at the time was it seemed to have two 4CX250s and their
sockets and I was thinking of nice linear material. I nearly fell off my chair when I read from the manual what it could do!  

I was hooked. At the time with a wife, three kids, a mortgage and a full-time job at which I traveled a lot I could not afford the real Collins
control head or power supplies. But, I did spring for all the Collins manuals and set about getting my 618T-3 on the air.

Back in those days there were many  electronic surplus outlets in and around Chicago. I managed to build a brute force 28VDC supply using
several huge high current filament transformers with wired series/parallel secondaries, got some 200amp diodes and some computer caps for
filtering. For the 400Hz at 115VAC I started with a rotary inverter --- nasty!!! Then I lucked into a nice SS inverter at a hamfest to do the job.

Then, I could not afford a real Collins control head by a long shot. But, I had access to many multi section rotary switches at these surplus stores.
So, I decided on a Nixie freq. readout and display. I built the display into an old Heathkit defunct Hi Fi amp cabinet that I bought at a ham fest
for a buck. I had to buy the actual switch section from Collins for the MHz codes and Nixie display. I wired up the other switches to do the
needed codes and used a separate section on each switch to light the Nixies. Lotsa dollars for those Collins MHz switch sections; but much
cheaper than a real control head. So, I wired the whole thing up and it worked like a charm. Looked great too. I'll bet the ONLY Nixie readout
control head for a 618T-3!!!

Eventually I figured out why it likely was surplused out by the Navy. It would only transmit for a couple of minutes then drop off the air. I can
imagine that it worked well on the bench then on the aircraft it would drop out, back to the bench and it worked well, etc. So, I scouted around
the surplus stores until I found a suitable relay and it worked perfectly with that one for many years. Eventually I sold the entire rig to a local ham
who just had to have it and who had deep pockets . . .

A few years ago I got the bug for one again now that I am retired. I bought one from a ham in Washington State. Obtained power supplies and
a 714E-3 control head. I found the test set at Fair Radio, some power cables and the test set to radio cable with the 60 pin connectors at each end
from a surplus dealer on the internet.

Much to my disappointment when I put power to it, it was DEAD DEAD DEAD!!!

Did some checking and found that the 18VDC power supply was at zero volts. I eventually found the problem to be a shorted electrolytic cap in that power
supply. A $1.20 repair part. BUT, US parts suppliers wanted upwards of $10 for shipping of this little item. So, I checked on ebay and found a lot of five of the
exact same caps listed by a seller in Rumania -- American made new Kemet caps at that for just $5 USD delivered. That 618T-3 works very well now after
I did a little tube replacement and alignment.

My very first on the air contact with this one happened to be on 40meters with a fellow ham who serviced them when he was in the US Navy.

Since then I have acquired five more 618T-3s one of which receives OK; but, does not transmit. I suspect an incorrect wiring issue in the tray to control
head line. This is my current project. It has the mobile type control head. I have not yet tried the others.

My goal is to eventually get them all up and running. I have enough control heads, five trays or interconnecting cables, two test harnesses, a 490T and
another Collins tuner for them and the module extender set.
I once again have a pretty complete manual set.

I used the sources that you listed on your 618T page as well as Newark for some of the connectors. Fair Radio was a very good source. But, I
did find three of the trays on ebay. Two of them were only $30 each complete with the 60 pin connector; BUT, shipping from Australia was a
REAL killer!!! Sigh --- as they seem to be made of unobtainium one has to pay the price.
 
I am very sorry that this is getting so long. But, maybe some of this is of interest to other 618T () users. I am no expert just lucky; but, if any
one has questions, I would be happy to try to help them.
73 de Bob K8RJ
GI4OYM

 
IZ2FLX

 

Dear John,
congratulations for your web site, I found many useful Tips when restoring my AN/ARC-102.
Thank you so much and  I'm happy to send some foto's of my 618T-3 .


Hi John,
Yesterday, I came across your beautiful WEB page.  
As you and others, I have the 618T illness. It is
incurable, I have also contracted the MRC-108 illness.  
I am pretty sure that the 618T illness is a strain 
of the 400Hz virus.           Frank, KF5RXV 
Carlo   IK2CNC , has two 618T's fully functional plus lots of other goodies. 
Lampros SV8FCF had his 618T up and running, home brew  28vdc to 400 cycle converter, 
Lampros also has a jeep, maybe some day he will get all the parts to make a MRC-95 mobile installation ??
 
I used to work on them in the Navy and got a job after the Navy because I could repair them. 

The ARC-94/RT-618T2 was used in the P-3 Orion (and on many commercial aircraft) while the ARC-102/RT-618T3 was used
on the SH-3 Sea King and the ARC-105/RT-618T1 was used on the EA-6B Prowler. I have no pics because I'm pretty sure that
would have gotten me courts marshaled. I still remember some about them.  Because they use mechanical tuning, they scared a lot of
techs into believing they were more complicated than they were.  Most of the time when a transceiver came in to the AIMD
(Aircraft Intermediate Maintenance Department), most of the time they weren't so much broken as badly out of tune.

Anyway, if I can be of assistance, shoot me an email.   ddstovall((at))charter.net
David Stovall
 
     


this map installed 1 Jan 2013

 

once upon a time I had a survey posted here,  and may of you responded.  and I enjoyed all  the great comments
however most of the time I would forget to check it for weeks at a time,  SO,  I removed it.
If you want to send pictures, emails, anything info , just send to jcwilson (a) ida.net 

Please ,  help save my band width,   SAVE your PDF's so you only download them once.
also IF you think you got $5 worth of useful info ,  you can donate at PayPal,  again jcwilson (at) ida.net.
 Please ,  this is just an Idea, and totally up to you.     
 

 

Some of the PDF's on this page came from 
http://www.liberatedmanuals.com/all.mpl
wheres there's MANY US Military manuals.

LOTS of military radio system manuals are at
http://bama.edebris.com/manuals/military/

 

 


   

 



HELP us get one of these working
looking for anyone that owns or has a working TSC-60 radio shelter..
not the one with HF-80 radios but the earlier version.
here are a few pictures. click picture to enlarge.

check this link for more pictures,                                                                                            
if you know anything about this radio   where to buy one,  anything     please email me k0ip (A) ida.net

OFF TOPIC,   I need a service manual for Harris RF-2301   contact webmaster
 

Disclaimer: all manuals provided for Amateur Radio use only.
to donate see this link