35.5 vs 34.7 (1 Viewer)

JRW

Premium RDF Member
Intermediate User
Premium Member
Joined
Mar 21, 2018
Messages
272
Reaction score
219
Awards
0
Location
Southern NJ
With all the Controls (FTC, etc) exert over radar, etc Frequencies/Power/Spectrum, I'm sort of surprised Stalker "won" those battles with a 100mW output at 35.5.

Are all radars operating in these frequency bands controlled by FTC? Or has the whole range of bands already been "authorized" for use in police radar gun applications?
 

InsipidMonkey

Premium Monkey
Advanced User
Premium Member
Acceptus
Joined
Mar 22, 2017
Messages
5,490
Reaction score
10,659
Awards
0
Location
New England
Are all radars operating in these frequency bands controlled by FTC? Or has the whole range of bands already been "authorized" for use in police radar gun applications?
The FCC is responsible for the radio spectrum, and has authorized the segment of Ka band radar from 33.4 to 36 GHz for police use. However, radar gun manufacturers only use three frequencies within this range, 33.8, 34.7, and 35.5 GHz (+/-100MHz). The reasons for this are interesting, and there is a post somewhere discussing it. I'll see if I can find it.
Vortex has some more info on Ka band here: Band Segmentation and Custom Sweeps - Vortex Radar

Edit: Found it.
Summary from another site and an interesting story on why Stalkers operate at 34.7:
jimbonzzz said:
Back in the early 90's when the Stalkers first came out, they were seeking permission from the FCC to develop and market a spread spectrum radar gun which would "hop" frequencies hundreds or thousands of times per second throughout the (then) wide Ka range. There were a few magazine articles published about this. Several objections were filed with the FCC to prevent this from happening, including an objection filed by Whistler.

A gun such as this would mean BIG problems for radar detectors. If implemented the way it is described, NO current detector would alert to it.

This gun never saw the light of day. But I also haven't found anyone who knows what became of the project either. I have asked several people in the engineering departments of all major detector manufacturers, as well as people in the radar gun industry. One person who used to be on this forum called up Stalker and asked about it, and the rep didn't even know what he was talking about. At any rate, it's safe to say that we don't need to worry about a frequency hopper being out on the roads, but I still wish I knew exactly what happened with the project. I really hope it isn't something they have been refining for the last 15 years!

Although the Stalkers manufactured today are on 34.7 GHz, the original Stalker ATR's were at 34.94 GHz. Reportedly, some early detectors that implemented Ka swept only segments around photo radar at 34.36 GHz and the Stalkers at 34.94 GHz. This was easier for them to do, since at the time most detectors used an oscillator around 11.558 GHz which produced a harmonic at 34.674 GHz, right in the middle of the band. It was easy for them to sweep 34.674 + IF and 34.674 - IF and leave a "hole" around 34.7 which remained unswept. Stalker realized this, and moved their operating frequency to this "hole" in order to defeat these detectors. Of course detectors eventually swept the whole wide Ka and later superwide, but the Stalker freq has remained on 34.7 to this day.

As for what you saw on 35.2 GHz: rumor has it that there were some old Stalker ATR's that operated on 35.2 GHz. GTO_04 is friends with a cop in a town nearby him that has a gun on this freq. From what I remember, he said it was slow to acquire a speed and had crappy range. Perhaps you encountered one of these old guns.

Rumor has it that there also might be Stalker ATR's out there on 34.2 GHz as well.

Jim
 
Last edited:

btmgov

ProCharger LS1 GOAT
Intermediate User
Premium Member
Joined
Jan 3, 2018
Messages
595
Reaction score
690
Awards
0
Location
Central Florida
I feel for you! 35.5 Sucks!
I see a few 35.5 guns around my area fairly regularly. My R3 seems to not have any problems picking them up from a way more than adequate distance. Of course, the terrain around here is nothing like the majority of what is dealt with in NC.......
 

Kennyc56

Ford Lover, I/O Hater!
Advanced User
Premium Member
Joined
Feb 22, 2018
Messages
2,298
Reaction score
5,368
Awards
0
Location
Eastern North Carolina
I see a few 35.5 guns around my area fairly regularly. My R3 seems to not have any problems picking them up from a way more than adequate distance. Of course, the terrain around here is nothing like the majority of what is dealt with in NC.......
The biggest threat in NC is these damn state troopers! They are very selective and wait as long as possible to pull the trigger.My R1 can get 35.5 at over 8 miles away,but that does me no good if I'm the only car on the road for 10 miles! They will wait sometimes till you are within as little as 500 feet or less and then pop your @ss! If you drive the same area for awhile,you will be ok once you learn all their hiding spots. As far as rolling IO goes,you will almost always see them in those chargers way before they shoot you.There is NO CO radar anywhere I drive till I go out of state,then I almost feel like I'm cheating! I've gotten some 35.5 alerts of 10 miles or more with my R1 and Redline-O on Vacation this summer in Texas and Tenn! I get them all the time around here as close as 200 feet! It will make your @ss stay alert I can promise you that!
 

btmgov

ProCharger LS1 GOAT
Intermediate User
Premium Member
Joined
Jan 3, 2018
Messages
595
Reaction score
690
Awards
0
Location
Central Florida
The biggest threat in NC is these damn state troopers! They are very selective and wait as long as possible to pull the trigger.My R1 can get 35.5 at over 8 miles away,but that does me no good if I'm the only car on the road for 10 miles! They will wait sometimes till you are within as little as 500 feet or less and then pop your @ss! If you drive the same area for awhile,you will be ok once you learn all their hiding spots. As far as rolling IO goes,you will almost always see them in those chargers way before they shoot you.There is NO CO radar anywhere I drive till I go out of state,then I almost feel like I'm cheating! I've gotten some 35.5 alerts of 10 miles or more with my R1 and Redline-O on Vacation this summer in Texas and Tenn! I get them all the time around here as close as 200 feet! It will make your @ss stay alert I can promise you that!
Yea, I know what you are talking about. I lived in NC for 7 years when I was involved in NASCAR. I was glad to get out of NC. I would never live there again with my driving style/vehicles.....lol
 

Kennyc56

Ford Lover, I/O Hater!
Advanced User
Premium Member
Joined
Feb 22, 2018
Messages
2,298
Reaction score
5,368
Awards
0
Location
Eastern North Carolina
Yea, I know what you are talking about. I lived in NC for 7 years when I was involved in NASCAR. I was glad to get out of NC. I would never live there again with my driving style/vehicles.....lol
Don't blame you one bit! I love NC but there are no other troopers or traffic cops ANYWHERE else like the ones we have here! Hell even the little punk @ss town cops try to use IO!
 

Deadhead1971

Instant-On Survivor
Advanced User
Premium Member
Joined
Dec 7, 2014
Messages
2,806
Reaction score
4,118
Awards
0
Location
Central NC
Don't blame you one bit! I love NC but there are no other troopers or traffic cops ANYWHERE else like the ones we have here! Hell even the little punk @ss town cops try to use IO!
I don’t encounter the NCHP that often running radar. It’s mostly the city police, and they run CO about 90% of the time. I see the NCHP coming and going but not often with radar around my municipal environment. I have been popped with instant on moving/rolling by the NCHP on the 2-lane highways between Clayton and Wilson on NC42.
 

tempnexus

Outside XYD's breathing heavily.
Advanced User
Premium Member
Joined
Jul 31, 2015
Messages
5,518
Reaction score
6,696
Awards
0
Location
DMV
I feel for you! 35.5 Sucks!
Virginia...aka Vagina...is full of 35.5 that's all they use

Want to feel nice warm wet and loved then come to Virginia. Virginia is for lovers!
 
Last edited:

DoctorWong

Learning to Drive
General User
Joined
Jul 6, 2018
Messages
12
Reaction score
7
Awards
0
Location
NC
Virginia...aka Vagina...is full of 35.5 that's all they use

Want to feel nice warm wet and loved then come to Virginia. Virginia is for lovers!
I disagree...I drive through VA once a month for work on my way to Philly and I have seen 34.7 stalker between Richmond and Fredericksburg Va on a consistent basis... by Va State Police. Most other areas are 35.5
 
Last edited:

sdrawkcaB

sdrawkcaB|Backwards
Advanced User
Premium Member
Joined
Mar 6, 2018
Messages
3,606
Reaction score
6,972
Awards
0
Are all radars operating in these frequency bands controlled by FTC? Or has the whole range of bands already been "authorized" for use in police radar gun applications?
Building on what @InsipidMonkey stated, Manufacturers manufacturing radar for speed measurement must have a valid license. The FCC is The Authority for controlling all radio spectrum allocation and spectrum authorization [read licensing] within the USA. Other countries and regions may have their own equivalent spectrum authorities in their respective territories.

Simply put, the FCC may allocate spectrum to a specific use, but manufacturers and operators may still be required to get authorization in the form of a license for that particular use within that spectrum. The specifics will vary depending on the allocation and purpose. Within the USA, The FCC requires that law enforcement organizations (LEOs) operating radar devices for speed measurement, must have valid operators licenses.

This is an awesome read here by another member. Member @chaz517 does a great job laying out why it is important for LEOs to have licenses for X, K, and Ka band even if they may already be legally entitled to do so by means of owning an active radio operators license. Read post #1 and #2. www.rdforum.org: K and Ka band radar licenses

Edit notes: added link for further reading.
 
Last edited:

Kennyc56

Ford Lover, I/O Hater!
Advanced User
Premium Member
Joined
Feb 22, 2018
Messages
2,298
Reaction score
5,368
Awards
0
Location
Eastern North Carolina
Virginia...aka Vagina...is full of 35.5 that's all they use

Want to feel nice warm wet and loved then come to Virginia. Virginia is for lovers!
Been to Va. many times,seen lots of 35.5 IO. They still can't compete with good ole' NC state troopers! I'll give them second place! Va. state troopers also suck!
 

tempnexus

Outside XYD's breathing heavily.
Advanced User
Premium Member
Joined
Jul 31, 2015
Messages
5,518
Reaction score
6,696
Awards
0
Location
DMV
I disagree...I drive through VA once a month for work on my way to Philly and I have seen 34.7 stalker between Richmond and Fredericksburg Va on a consistent basis... by Va State Police. Most other areas are 35.5
Yeah Sorry most of DC +/- 20 miles of the DC border for me and my wife in terms of VA traffic we don't venture to anything south of Manassas i.e. Arkansas of VA.
 

sdrawkcaB

sdrawkcaB|Backwards
Advanced User
Premium Member
Joined
Mar 6, 2018
Messages
3,606
Reaction score
6,972
Awards
0
The Stalker ATRs are ridiculously high powered compared to most radar guns. Also, the 35.5 guns tend to be lower power than other Ka band guns for some reason.

Ka band guns
Frequency (GHz)Radar GunPower OutputPower Density
33.8MPH BEE III12-30mW nominal (50mW max)<2mW/sq cm
34.7Stalker ATR50mW nominal (100mW max)4mW/sq cm
34.7Stalker DSR15mW nominal (50mW max)<2mW/sq cm
35.5Decatur Genesis II12mW nominal (15mW max)<0.5mW/sq cm
35.5Kustom Talon15mW nominal (25mW max)<5mW/sq cm
I came across this thread again today. What's the source for this table data? I'm just curious so I can do some more reading. Plus, citations are cool (when they're on the forum and not at the side of a road). :p
 

Hahns52

Crackheads and Debutantes
Advanced User
Premium Member
Joined
Aug 28, 2012
Messages
1,879
Reaction score
2,206
Awards
0
Location
SW WA
FWIW, in my limited testing, I found the Decatur G2 35.5 Ka conical antenna was the most detectable and the Kustom 35.5 Ka antenna was the least detectable of the guns I had on hand at the time.

yrLCc5U.jpg
 

InsipidMonkey

Premium Monkey
Advanced User
Premium Member
Acceptus
Joined
Mar 22, 2017
Messages
5,490
Reaction score
10,659
Awards
0
Location
New England
I came across this thread again today. What's the source for this table data? I'm just curious so I can do some more reading. Plus, citations are cool (when they're on the forum and not at the side of a road). :p
Good call! As a scientist, I should know better :doh:

If I remember correctly these were all taken from the FCC filings (either user manuals or test reports). Subsequent to this, I figured out how to search the Canadian equivalent of the US FCC as well: Canadian Radio Equipment List (eg FCC Canada)

It appears there are some differences in US and Canadian version radar guns as far as allowed frequency and output go, as @Heywood pointed out.
 

asleeper

Premium RDF Member
Advanced User
Premium Member
Joined
Jun 12, 2011
Messages
1,073
Reaction score
1,776
Awards
0
Location
Virginia
Virginia...aka Vagina...is full of 35.5 that's all they use

Want to feel nice warm wet and loved then come to Virginia. Virginia is for lovers!
While VA is mostly 35.5 (state and local), 34.7 does exist, albeit to a lesser degree. I know LoCo uses both (34.7 and 35.5).
 

Brainstorm69

TXCTG 2016 MOTY
Advanced User
Premium Member
Joined
May 23, 2015
Messages
8,773
Reaction score
18,062
Awards
0
Location
Lone Star State
The FCC is responsible for the radio spectrum, and has authorized the segment of Ka band radar from 33.4 to 36 GHz for police use. However, radar gun manufacturers only use three frequencies within this range, 33.8, 34.7, and 35.5 GHz (+/-100MHz). The reasons for this are interesting, and there is a post somewhere discussing it. I'll see if I can find it.
Vortex has some more info on Ka band here: Band Segmentation and Custom Sweeps - Vortex Radar

Edit: Found it.
Summary from another site and an interesting story on why Stalkers operate at 34.7:

jimbonzzz said:

Back in the early 90's when the Stalkers first came out, they were seeking permission from the FCC to develop and market a spread spectrum radar gun which would "hop" frequencies hundreds or thousands of times per second throughout the (then) wide Ka range. There were a few magazine articles published about this. Several objections were filed with the FCC to prevent this from happening, including an objection filed by Whistler.

A gun such as this would mean BIG problems for radar detectors. If implemented the way it is described, NO current detector would alert to it.

This gun never saw the light of day. But I also haven't found anyone who knows what became of the project either. I have asked several people in the engineering departments of all major detector manufacturers, as well as people in the radar gun industry. One person who used to be on this forum called up Stalker and asked about it, and the rep didn't even know what he was talking about. At any rate, it's safe to say that we don't need to worry about a frequency hopper being out on the roads, but I still wish I knew exactly what happened with the project. I really hope it isn't something they have been refining for the last 15 years!

Although the Stalkers manufactured today are on 34.7 GHz, the original Stalker ATR's were at 34.94 GHz. Reportedly, some early detectors that implemented Ka swept only segments around photo radar at 34.36 GHz and the Stalkers at 34.94 GHz. This was easier for them to do, since at the time most detectors used an oscillator around 11.558 GHz which produced a harmonic at 34.674 GHz, right in the middle of the band. It was easy for them to sweep 34.674 + IF and 34.674 - IF and leave a "hole" around 34.7 which remained unswept. Stalker realized this, and moved their operating frequency to this "hole" in order to defeat these detectors. Of course detectors eventually swept the whole wide Ka and later superwide, but the Stalker freq has remained on 34.7 to this day.

As for what you saw on 35.2 GHz: rumor has it that there were some old Stalker ATR's that operated on 35.2 GHz. GTO_04 is friends with a cop in a town nearby him that has a gun on this freq. From what I remember, he said it was slow to acquire a speed and had crappy range. Perhaps you encountered one of these old guns.

Rumor has it that there also might be Stalker ATR's out there on 34.2 GHz as well.

Jim
Anyone else find it interesting how this frequency hopping radar and Jim mentioning that no detector would be able to detect corresponds with what @Jon at Radenso was discussing about why some cars' BSM doesn't make detectors false?

 
Last edited:

Users Who Are Viewing This Thread (Users: 0, Guests: 0)

Unregistered User Ad


ATTENTION: Want ads to disappear? Register for an account here - it's free and NO ADS ARE DISPLAYED TO REGISTERED MEMBERS! Thanks!

Donation drives

RDF Server & License Fees (JULY 2019) (ACTIVE)

This donation drive covers the server and licensing fees for RDF for the month of July 2019...
Goal
$643.00
Earned
$95.00
This donation drive ends in

Latest threads

Latest posts

Social Group Activity

Forum statistics

Threads
83,913
Messages
1,256,160
Members
19,479
Latest member
faring
Top