Hi Guys! Thanks to Dave about using the 2 transformers
back to back to make an isolation transformer. I wish I
had understood that in 1968. And you sure are right
about not exceeding the specs of the transformers!
I forgot one story about the range of the Kt-195.
As I mentioned, mine was built wrong and it put out
the most on 2100 kHz (along with some other output
products.) We kept doing our radio shows anyway.
It was a real intermittent schedule and being on the
marine band or the 120 meter international broadcast
band (I think) didn't bother us.
The KT-195 was on a counter in my parent's rec-room (sp?)
A ten foot wire lay on the floor. (Cause in those days I
think the rule was ten feet and not 3 meters like it is now.)
The ten foot wire was a piece of 300 ohm twin lead. I was
just using one side. We would let a tape run, or a record.
I would take my Korrsonic (sp/) multiband portable radio
up to my room or over to my buddies house about 150
feet away. We heard it OK there.
What I didn't know, and was later told by another really good
friend is that he was picking it up 3000 feet away on the far
side of the golf course (on the other side of my street) and across a pond at his house. It was S7 on the meter of a Knight R100A general
coverage receiver. In forty years,(and I am still in touch with both
friends) we have never been able to explain this long range with
the transmitting antenna lying on the rec-room floor.
All I can think of is that RF might have also been going into the
house wiring from the transmitter circuit and was being
radiated that way. Oh yeah, my friend 3000 feet away did have
a ninety foot outside wire receiving antenna.
I guess we'll never really know!
Thanks guys!
I just saw MRAM's picture and schematic of the
KT-195!
Wow! That's it!!!! Good for you!!!!
THAT'S IT !!!!!!!!!! The KT - 195 is the unit I had as kid! Thank you all SO much for digging this up for me. I really appreciate it. If anyone ever comes across one of these, please let me know. I would love to own one again just for "old times’ sake". Thanks again,
gronsk
Having calmed down now a little bit, I wanted
to thank all of you again for helping me find my
old KT-195. A very special thank you also to
MICRO1700 for nailing this one down for me and
MRAM 1500kHz for the GREAT picture. MICRO1700
I hope your vision problem doesn’t keep you from
posting on this forum. I can read your posts
with no problem at all and I hope you can read my
reply without too much trouble. Thanks again to all.
gronsk
Hi Gonsk and everybody else!
Gonsk, thanks a lot for your concern with my vision.
I just do things slower and one thing at a time.
I was THRILLED that we all got to talk about the
KT-195.
I may not be around all the time. But I am out here
and I will return. I've enjoyed this site for years.
Talking about the KT-195 was just what got me to
sign up.
Take care!
Hey, it's really great to find people that followed similar paths and enjoy reliving some of it. Radio has been a big part of my life since I was a kid and Part 15 operations (along with Ham radio and my day job) keep it going.
I'll keep tinkering with my KT-195. I updated the schematic with recent changes and plan to take some pix of the RF shown on the oscilloscope so you can see what the output looks like.
Added oscilloscope pix 1/30/09
I'm pleased that I could provide a glimpse into the past for you too.
Hi MRAM! That's a bunch of great shots
of the KT-195 on the scope!
Very cool!
Hello All!
My name is Ted and I've been reading your info on this little unit.
I first had one back in late 60's when I dabbled in radio. It was a fun and a learning Experience. Now, I'm in my 28th year in radio broad-
casting and 16th year at WFIL/WNTP in Philly as chief operator AND
for my birthday this year I found online and bought this unit BRAND NEW in its original box.original Hitachi tubes and instruction sheet.
I fired it up for the very first time and it worked. Boy, this takes me back.
Brand new in the box! What a find.
Say... Would you consider scanning the instruction sheet and either emailing or posting on line? I'd really like to complete mine with the original paperwork.
Hi! I had the Lafayette LA-23. On my unit, The rotary pot on the left was the on/off microphone volume control. The slide swith in the middle was labled "broadcast" and "amplify". (In the "amplify" position the unit worked as a PA amplifier) And the small screwdriver control was for frequency.
Range out of the box wasn't bad...100' or so....but then a friend brought me an article from S-9 magazine (1967, I think..)showing me how to hook up my LA-23 to a 102" CB whip with a loading coil in the middle, and a little tuning curcuit...a 365uuf cap. and a 280uh coil...so I could match the LA-23 properly to the CB whip. WOW DID THAT WORK!!!!! My former 100'range went up to a half-a-mile! I had so much fun with that thing for the next 6 months or so until the bug for more range hit me, and I ended up using a 50watt 160 meter ham transmitter for my "part 15 station". That went 5 miles or more and eventually brought the FCC into town about a year and a half later. Those were fun times. Thanks for the memories!
By the way, I don't have the LA-23 anymore, but I DO have the old catalog I ordered it from. Want a picture?
I recently purchased the original assembly/operation manual for the Lafayette KT-195 AM Broadcaster.
I have updated the schematics on my KT-195 PAGE if anyone is interested.
There were some incorrect part values on the hand drawn schematic from another website.
The modified for Plate Modulation schematic has notations for the circuit changes.
That is a good looking oscillator that I have not seen before.
The circuit looks similar to an earlier Knight Kit that had the tubes exposed on the outside-top.
It doesn't work, and needs a 36AM3B rectifier tube.
But even if it had the rectifier, it still wouldn't work,
it's a mess.
If I was able, I would do the MRAM mods and use an
isolation transformer.
Meanwhile, it sits on the shelf and looks cool.
Best Wishes,
Bruce, DOGRADIO STUDIO 2
Anyone looking for one of these, don't forget the different model number that was used for the factory assembled units. The KT-195 already assembled was the LA-23.
Easiest way to keep from getting zapped: Put a voltmeter between the chassis and ground. If you get a reading on the meter, turn the plug around. Then you won't get a reading and you're safe.
Also, if you put a little resonant tank curcuit at the RF output and feed it into a 3 meter whip with a base loading coil, (like you would for a Procaster or Rangemaster) and add a ground system, the little Lafayette will kick some butt! Only problem you'll have is -- everytime you try to tune the tank curcuit, the frequency will change. You have to juggle the tank curcuit tuning with the frequency tuning on the transmitter while using a field strength meter so you can tell which frequency is the one being peaked. You'll hear a bunch of different signals...gotta find the REAL one. (Oh the joys of the old LC circuits!)