radar questions
 

In article ,
"Lynn Coffelt" wrote:

There were some strange diodes in the klystron tune regulated voltage source
that were no longer available (this in about maybe 1978). Dumb thing would
drift out of front panel tuning range periodically. Could bring it right
back with chassis pot, of course, but owner frowned on that and I never did
get paid! Don't blame him a bit.

The KRA124/248/448 didn't have a Klystron for an LO, but was the first
of the Second Generation Radars, and used an XBand Gun Diode Osc. As
I recall Furuno last used a 2K25 Klystron in the KRA 121 Series Radars
which was before Northen picked up the Furuno Dealership. Don
Hollingsworth Sr. at G & L Marine was the KRA-121 expert and has always
been the "Go To Guy" for Marine Radar Technical Information, even when
he was the Raytheon Marine Tech (Ray 1500/1700/1900) for the NorthWest,
and worked for U.G. Allen.

Man that does date me, in the North Pacific Marine Electronic Community.

Bruce in alaska
--
add a 2 before @

radar questions
 

Dunno about the model, but I was hanging out in the wheel house of one of the
Monterey dive boats a few years ago while we were coming back from a couple
of dives off Big Sur. It's grey day, but the marine layer was up off the water and
visibility was maybe four miles. At about Cypress Pt. the radar starts showing a
BIG target dead ahead. a couple of miles.

Now, A) we don't get big targets in Monterey very often, and esp not in water that
shallow, and B) we can't see any big targets visually. A couple of small boats, and the
Pt. Pinos buoy a couple of miles out, but nothing near that big. When the
range gets down to about a half mile, Capt. Phil starts looking kinda nervous. Then
the marine layer lifts a bit, and: Goodyear Blimp. ;-)

"Bruce in Alaska" wrote in message ...
In article ,
"Lynn Coffelt" wrote:

There were some strange diodes in the klystron tune regulated voltage source
that were no longer available (this in about maybe 1978). Dumb thing would
drift out of front panel tuning range periodically. Could bring it right
back with chassis pot, of course, but owner frowned on that and I never did
get paid! Don't blame him a bit.

The KRA124/248/448 didn't have a Klystron for an LO, but was the first
of the Second Generation Radars, and used an XBand Gun Diode Osc. As
I recall Furuno last used a 2K25 Klystron in the KRA 121 Series Radars
which was before Northen picked up the Furuno Dealership. Don
Hollingsworth Sr. at G & L Marine was the KRA-121 expert and has always
been the "Go To Guy" for Marine Radar Technical Information, even when
he was the Raytheon Marine Tech (Ray 1500/1700/1900) for the NorthWest,
and worked for U.G. Allen.

Man that does date me, in the North Pacific Marine Electronic Community.

Bruce in alaska
--
add a 2 before @

radar questions
 

In article ,
"Chuck Tribolet" wrote:

Dunno about the model, but I was hanging out in the wheel house of one of the
Monterey dive boats a few years ago while we were coming back from a couple
of dives off Big Sur. It's grey day, but the marine layer was up off the
water and
visibility was maybe four miles. At about Cypress Pt. the radar starts
showing a
BIG target dead ahead. a couple of miles.

Now, A) we don't get big targets in Monterey very often, and esp not in water
that
shallow, and B) we can't see any big targets visually. A couple of small
boats, and the
Pt. Pinos buoy a couple of miles out, but nothing near that big. When the
range gets down to about a half mile, Capt. Phil starts looking kinda
nervous. Then
the marine layer lifts a bit, and: Goodyear Blimp. ;-)


I always liked to see what skippers would do when they saw a target on
their radar, that was moving at 100Kts directly at them. FloatPlanes
flying at 500Ft, look really strange on Marine Radars....

Bruce in alaska
--
add a 2 before @

radar questions
 

"Bruce in Alaska" wrote in message
...
In article ,
"Lynn Coffelt" wrote:

There were some strange diodes in the klystron tune regulated voltage
source
that were no longer available (this in about maybe 1978). Dumb thing
would
drift out of front panel tuning range periodically. Could bring it right
back with chassis pot, of course, but owner frowned on that and I never
did
get paid! Don't blame him a bit.

The KRA124/248/448 didn't have a Klystron for an LO, but was the first
of the Second Generation Radars, and used an XBand Gun Diode Osc. As
I recall Furuno last used a 2K25 Klystron in the KRA 121 Series Radars
which was before Northen picked up the Furuno Dealership. Don
Hollingsworth Sr. at G & L Marine was the KRA-121 expert and has always
been the "Go To Guy" for Marine Radar Technical Information, even when
he was the Raytheon Marine Tech (Ray 1500/1700/1900) for the NorthWest,
and worked for U.G. Allen.

Man that does date me, in the North Pacific Marine Electronic Community.

Bruce in alaska

That's what I get for letting my mouth overrun my holeridden memory.
The Konel that I was remembering did have a Klystron, and came in an "up" or
"down" transceiver model. The one on the yacht/halibut boat had the "up"
version and I had to make a test cable to run the transceiver in the pilot
house. It would see a mile or two with the waveguide coupler pointed out the
window. Boss insisted on a dummy load when he was around, but that made the
NE-2 on a stick, or echoes from down the bay unavailable. (I think you
mentioned once that "real" technicians didn't bother with the stick)
I guess I didn't get Furuno tech bulletins farmed out to me in
Anacortes until maybe 1979....... isn't that about the time the "toilet
bowl" went from KRA112 to KRA124? (and about the same time as the phenolic
based boards in the display started burning between lands all over the
place? Best troubleshooting was in a dark room, turning off and on, watching
for glow or sparks. Of course it was hard to see smoke then, but you could
smell it pretty quickly.

Old Chief Lynn

radar questions
 

OK, KRA116!

radar questions
 

In article ,
"Lynn Coffelt" wrote:

That's what I get for letting my mouth overrun my holeridden memory.
The Konel that I was remembering did have a Klystron, and came in an "up" or
"down" transceiver model. The one on the yacht/halibut boat had the "up"
version and I had to make a test cable to run the transceiver in the pilot
house. It would see a mile or two with the waveguide coupler pointed out the
window. Boss insisted on a dummy load when he was around, but that made the
NE-2 on a stick, or echoes from down the bay unavailable. (I think you
mentioned once that "real" technicians didn't bother with the stick)
I guess I didn't get Furuno tech bulletins farmed out to me in
Anacortes until maybe 1979....... isn't that about the time the "toilet
bowl" went from KRA112 to KRA124? (and about the same time as the phenolic
based boards in the display started burning between lands all over the
place? Best troubleshooting was in a dark room, turning off and on, watching
for glow or sparks. Of course it was hard to see smoke then, but you could
smell it pretty quickly.

Old Chief Lynn



Your confusing the KRA-124/248/448 Series, KRA1121 which preceeded it,
with the KRA-116 (ToiletBowl) and it's later cousins, the KRA-240 and
360. The Toilet Bowls all had HV Breakdown problems on the Main Display
boards, up untill the 240MKII's, when they redesigned the Trace paths
for the HV Section. The KRA-121's had 2K25 Klystrons, and were First
Generation, Marine Radars. KRA-124 Series were the first of the Second
Generation Radars, that had Gunn Diode LO's and the MKII versions had
Ring Circulators, instead of TR Cells. Third Generation Radars had
MMIC's, and Ring Circulators like the 1600's, 2400's and 701/1001 Series.
I put one of the first KRA-116's on the little Harbor Tug Western Towboat
had called the Wasp. It was a preproduction unit and ran for 6 hours
before the Inverter Board in the Powersupply went up in smoke. Old
Man Shrewsbury, wasn't so sure that these Jap Radars were any good after
that fiasco, cause it took a week to get a new board out of the factory
in Japan. Now if you look on any of the Western Towboat Tugs you will
see 100% Furuno Radars everywhere in their Fleet.

Bruce in alaska
--
add a 2 before @

radar questions
 

.. Your confusing the KRA-124/248/448 Series, KRA1121 which preceeded it,
with the KRA-116 (ToiletBowl) and it's later cousins, the KRA-240 and
360. The Toilet Bowls all had HV Breakdown problems on the Main Display
boards, up untill the 240MKII's, when they redesigned the Trace paths
for the HV Section. The KRA-121's had 2K25 Klystrons, and were First
Generation, Marine Radars. KRA-124 Series were the first of the Second
Generation Radars, that had Gunn Diode LO's and the MKII versions had
Ring Circulators, instead of TR Cells. Third Generation Radars had
MMIC's, and Ring Circulators like the 1600's, 2400's and 701/1001 Series.
I put one of the first KRA-116's on the little Harbor Tug Western Towboat
had called the Wasp. It was a preproduction unit and ran for 6 hours
before the Inverter Board in the Powersupply went up in smoke. Old
Man Shrewsbury, wasn't so sure that these Jap Radars were any good after
that fiasco, cause it took a week to get a new board out of the factory
in Japan. Now if you look on any of the Western Towboat Tugs you will
see 100% Furuno Radars everywhere in their Fleet.

Bruce in alaska

Yup, I did confuse the KRA1121 with the KRA-124 to 448 series, The only
1121 I worked on, then was the one on the Yacht/halibut boat. The KRA-124 to
448's were about 50% of the installations on our ferry contract. The rest
were Decca group 9's. The toilet bowl, was surely an interesting concept,
and when they became FR240's and up, with a vented toilet bowl they were a
real class act. (for the time...... of course)
Thanks for helping clear some fog!
Old Chief Lynn