Patent Application
20050195337
Using two, double Sideband Full Carrier AM Transmitters, to produce Stereo and one other Transmitter, either AM, NBFM or Single Sideband Suppress Carrier in the AM Band to produce the Slow Scan Video on AM Band 8 khz Down from the main Audio Carrier. With the use of a Diplexer, an Antenna Tuner and an Antenna Stacker Earth grounded, will make for good separation of the AM Station's Audio and Video carriers within a 15 khz Bandwidth.
Single Sideband Suppress Carrier will work well for the Slow Scan Video also but like NBFM, one would need special Receivers for those two Modulations.
Using NBFM transmitter in the AM Band will enable the VC-H1 to use the fast FM mode; the Fax like beeps will be very faint over the AM Receiver if tuned to the Video Frequency.
This system for slow scan Video can be used for FM Radio, using the RDS 57 khz or the SCA 67 khz above the main carrier of the FM channel. This Freeze Frame Video known as SSTV.
FSTV operators could run SSTV over their SAP (second Audio Programmer) of the commercial TV station. Some Amateur TV operators do run Video on the AM Carrier, Audio on the FM-1 Carrier, and SSTV on the FM-2 Carrier. (AM 439 and TSC-70.)
This AM Video System is different from Mr. Khan's AM Audio/Data System because the Data is embedded in the audio.
SSTV will not mix with Audio, that is why there is a Frequency difference in the Raven System, furthermore the FCC does not consider SSTV Picture information as Data.
The Auto Switch LM555 Timing Circuit (Designed and built by this Inventor) enables one to broadcast one to two Pictures per Minute. Right now the IBOC Digital AM System requires a channel Bandwidth of 30 khz and no Video as of yet!!!
Present invention enables the Audio and Slow Scan TV Signals to be transmitted over the same 15 khz Wide Channel on the AM Band. Example: 690 khz to 705 khz in which the Video Carrier is at 692 khz @BW of 4 khz (690 khz to 694 khz) and the Audio Carrier is at 700 khz @BW of 10 khz (695 khz to 705 khz). *Please Note 15 khz Bandwidth @ 700 khz can also mean 692.5 khz to 707.5 khz.
For AM Video an AM Analog Radio with an Analog tuner can be directly tuned to 692 khz. An Analog Radio with a Digital tuner, can be tuned to 690 khz for the Video. By listening the Fax like Beeps, before plugging in a slow scan Converter in the Headphone Jack of the AM Receiver being used for the Video. (For FM Video, the same can be done by Using an FM or SSB-SC Receiver for the Band being used), The same Analog Receiver will tune in the Audio at 700 khz.
A walkman style RCA AM FM Stereo Cassette player # RP-1872C was used to check the on Air Frequencies, also used was a Radio Shack DMM 22-174B set for HZ/KHZ and a GW-INSTEK Digital Frequency Counter# GCF-8010H to check frequency.
All Transmitters used are Hobby Broadcast Equipment and are of the name Brand Ramsey and North Country Radio.
Three receivers were used, two for receiving the stereo in the same manner used for receiving the Khan AM Stereo System. Except in the case of the Raven/RVS/RVN, the right channel receiver is tuned right on the frequency due to the Phase Lock Loop of the AM 25 Transmitter, the Left Channel Receiver is tuned slightly off the Left of the frequency.
Now the third AM receiver needs the use of a Slow Scan Converter like the Kenwood VC-H1, such as the one used at the Transmitter site, the only difference being the VC-H1 at the Transmitter Site is in the Auto Transmit mode (once every 3 minutes), which is too slow for commercial broadcast use. A 555 Timing Circuit was built to cause the auto mode to transmit a new Picture every minute, and with * Live Action Capture* Built in by Kenwood, there is no need to stop the action or pose to send a new Picture. Furthermore, the VC-H1 at the transmitter site will not receive when it is in the Auto Transmitter Mode, therefore will be no video interference from other Radio Stations using the same system.
Other Drawings are Schematics of: Ramsey STC-1; Ramsey AM 25 Transmitter; Ramsey AM 1 Transmitter North Country Radio AM 88 Transmitter; Schematics of −45 Degrees +45 Degrees Right and Left Channel Phase Networks.; Kenwood VC-H1 cable setups (two sheets) also LM 555 Auto switch. One Notarized log of three hand drawings on one sheet, the testing of AM Audio on the AM Band, first test of FM Picture FM Band, second test of AM Picture AM Band and finally FM Picture AM Band. (All tests were AM Audio on AM Band)
One, VHS Tape of on Air Operations of the RAVEN/RVS/RVN.
Four pages, of colored Pictures, of RAVEN/RVS/RVN in action.
After the Ramsey STC-1 Stereo Limiter a Ramsey AM one Transmitter with a disabled Oscillator (C7, Q6, and Q5 have been removed).
The Ramsey AM PRO-25 Transmitter with its ANT. out, going into the RF of the AM-1 Transmitter Via R10.
Also the AM PRO-25. Another Q9 was add 9 Collector, Base-to-Base, and Emitter-to-Emitter) in parallel with the original Q9, both with cooling fins.
Changed R23 variable resistor from 1KOHM to 10 KOHM and changed R5 from 1KOHM fixed Resistor to a 10 KOHM variable Resistor and lastly added a 12 Volt Cooling fan from an old computer for extra strong cooling; now the top cover no longer fits the AM PRO 25. A Kenwood VC-H1 inputs into a De-Emphasis Network, that inputs into an AM 1, whose filter network L3 is unchanged but C12 and C14 Values have been changed from 0.0022 UF to 0.02 UF, to obtain the Band width of 4 khz and that output is then Coupled to the Main Antenna Along with the output of the Stereo Signal from the AM 1-AM 25 Transmitter. Both the audio and the video Transmitter system use the same antenna with no loss of power due to the antenna Tuner and Diplexer.
AM 88 Transmitter can be used for FM Pictures in the AM Band, therefore there is no need to modify an AM 1 for that Purpose.
The Video Power Recommendations are for AM Pictures. Antenna height should be considered for FM Pictures, such as, if the Antenna height is 1160 Feet then the maximum Video power would be any where from 3 kw to 6 kw, for Commercial Broadcasting.
Magazine article by Harry Maynard: AM STEREO ITS STEREO ITS TIME HAS COME; October 1976 Magazine: NUTS & VOLTS article: Just The Fax by Michael Banks
McGraw-Hill Books: Electronic Communications: PP. 63 and 92; Louis E. Frenzel Third Edition.
Tab Books: The Complete Handbook of Slow Scan-TV by Dave Ingram
Radio Shack 2002 Catalog: A Brief Description of RDS (FM Radio Data Service)
Internet: Slow Scan-TV History 1970 W7FEN: Single Sideband-Suppress Carrier; Lower Sideband Audio; Upper Sideband Video.
Internet: Commercial AM Transmitters; Articles on Power Side and Cam D. Kahn Communications (No Schematics)
Internet: Advertisement; Low Power AM Part-73; AM-30P, AM-60P and AM-100P LPB, Inc.
Hobby Broadcast AM Part 15: AM-1 and AM PRO-25, Schematic Study and Kit Building Ramsey Electronics.
| Number | Date | Country | |
|---|---|---|---|
| 60463103 | Apr 2003 | US |
