Linear amplifier 4cx5000a

tag:blogger.com,1999:blog-22697934509932929302011-10-02T03:24:11.236-07:00Linear amplifier 4cx5000a4cx5000a linear amplifier john 5-19 lamia. GROUNDED SCREΕN AMPLIFIER USING THE EIMAC TUBE 4CX5000Α.5-19 lamianoreply@blogger.comBlogger11100tag:blogger.com,1999:blog-2269793450993292930.post-29408495415177365812008-05-21T06:16:00.000-07:002011-10-02T02:57:49.130-07:00JOHN 5-19 LAMIA *HIGH POWER AMPLIFIER 4CX5000A*<o:p></o:p> <meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style> An AM Transmitter Modification and Construction Project.<meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style><meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style> <style>  </style>The Screen of the tube is physically connected to the ground.<o:p></o:p> <o:p></o:p>The 'grounded screen' may be a bit confusing to those of us used to using tetrodes in the more conventional manner, with the cathode at chassis potential. Due to the design of this cavity, the screen is indeed at "ground" for RF; for DC, it can be more precisely described as being connected directly to the chassis. This requires a bit more complexity in the design of the power supply.<a href="http://www.youtube.com/watch?v=v2bgI_mXr5E&feature=player_embedded"> </a>The grounded screen configuration results in better isolation of plate from grid circuits; therefore, better over-all stability!!!! <a href="http://www.youtube.com/watch?v=v2bgI_mXr5E&feature=player_embedded">Power output over 10kw could then be expected.</a> Power was measured with a Bird 43 wattmeter and a 10 KW slug (<a href="http://www.youtube.com/watch?v=v2bgI_mXr5E&feature=player_embedded">Frequency Band 0.45-2.5 mhz</a>) <a href="http://5-19lamia.blogspot.com/">HOME MADE LINEAR AMPLIFIER 4CX5000A</a> ...................... 1690 KHZ AM<o:p></o:p><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_DeH_ysJr0eM/SdaHxLFBV9I/AAAAAAAAAYc/Y9n6FTrJfr4/s1600-h/ON+AIR.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 310px; height: 60px;" src="http://2.bp.blogspot.com/_DeH_ysJr0eM/SdaHxLFBV9I/AAAAAAAAAYc/Y9n6FTrJfr4/s400/ON+AIR.jpg" alt="" id="BLOGGER_PHOTO_ID_5320589288642009042" border="0" /></a>This is a 4CX5000a grid driven amplifier that is built like a tank. The unit is considerably over designed as can be seen in the pictures documenting the construction. The unit requires a separate screen power supply and High Voltage power supply. The documentation indicates a well thought out design and construction technique. <meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style> Below you can find some pictures of my "Shack".<o:p></o:p> Click on the photo description for a larger picture. <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_DeH_ysJr0eM/S2l34y36aqI/AAAAAAAAAes/EvVsWpv89yA/s1600-h/linear+4cx5000a.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://1.bp.blogspot.com/_DeH_ysJr0eM/S2l34y36aqI/AAAAAAAAAes/EvVsWpv89yA/s400/linear+4cx5000a.jpg" alt="" id="BLOGGER_PHOTO_ID_5434006243011881634" border="0" /></a> Output Power In order to achieve full power output over 10000 watts continuous carrier, an input power approximately 10 to 40 watts is required. If your delivers more output power, reduce the drive level. For the amplifier RF output, I used an LC type connectors at the time of construction. <o:p></o:p>The LC type seems to handle the power levels without any problems (so far!).<o:p></o:p> <o:p> </o:p> <o:p> </o:p> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_DeH_ysJr0eM/SDVhWYJSesI/AAAAAAAAACQ/lNNzPo_zgEo/s1600-h/4cx5000a-5-195.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 303px;" src="http://3.bp.blogspot.com/_DeH_ysJr0eM/SDVhWYJSesI/AAAAAAAAACQ/lNNzPo_zgEo/s400/4cx5000a-5-195.jpg" alt="" id="BLOGGER_PHOTO_ID_5203171981562903234" border="0" /></a> Tube Protection The linear has a very sophisticated tube protection circuitry, designed to protect excessive plate current, screen grid current, screen grid voltage, bias voltage, overdrive, SWR. The tube is also protected from excessive temperature by continuously monitoring the required airflow temperature. In case of any fault, the amplifier is automatically cut off. A resistor in the B+ circuit and a MOV in the screen circuit further protects the tube and the power supply from a possible tube internal flash-over.<o:p></o:p> <o:p> </o:p> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_DeH_ysJr0eM/SDVgAoJSenI/AAAAAAAAABo/0n9EeSDjZfk/s1600-h/4cx5000a-5-19.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://4.bp.blogspot.com/_DeH_ysJr0eM/SDVgAoJSenI/AAAAAAAAABo/0n9EeSDjZfk/s400/4cx5000a-5-19.jpg" alt="" id="BLOGGER_PHOTO_ID_5203170508389120626" border="0" /></a> In the center of the photo is a shaped parasitic choke with two, 3 watt, 100 ohm carbon resistors across it.<a href="http://3.bp.blogspot.com/_DeH_ysJr0eM/TRohtn5EhQI/AAAAAAAAAn8/ZjSRHG08-x0/s1600/linear%2B4cx5000a.jpg1.jpg"><img style="display: block; margin: 0px auto 10px; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://3.bp.blogspot.com/_DeH_ysJr0eM/TRohtn5EhQI/AAAAAAAAAn8/ZjSRHG08-x0/s400/linear%2B4cx5000a.jpg1.jpg" alt="" id="BLOGGER_PHOTO_ID_5555790158001112322" border="0" /></a>Tube The linear operates with one <a href="http://www.g8wrb.org/data/Eimac/4CX5000A.pdf">4cx5000a/8170</a> tube, in Class AB1 with a plate dissipation of 6000 watts.Constructed primarily for military communication, this tube is physically and electrically exceptional rugged and with additional sophisticated protection circuitry incorporated, the linear is almost indestructible. The 4cx5000a/8170 tube is a compact high slope and when operated under normal conditions, will last a very long time. Class AB1 amplifiers are roughly 60% efficient. The zero-signal anode-current in a Class AB1 amplifier is normally set to about 20% of the maximum-signal single-tone anode-current. In a typical HF amplifier, the drive power required for Class AB1 operation is roughly 1% to 2% of the output power. Most of the tubes that are used in Class AB1 RF amplifier service are tetrodes and pentodes--devices that have the advantage of grid-to-screen amplification.<o:p> </o:p><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_DeH_ysJr0eM/SD8mwYJSfQI/AAAAAAAAAHQ/vrf9LBeNaUI/s1600-h/roller12.JPG"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://1.bp.blogspot.com/_DeH_ysJr0eM/SD8mwYJSfQI/AAAAAAAAAHQ/vrf9LBeNaUI/s400/roller12.JPG" alt="" id="BLOGGER_PHOTO_ID_5205922306820570370" border="0" /></a> Cooling A lot of attention was given to the design of the linear cooling system. A pressurized forced air cooling to achieve with a rugged temperature controlled 850 CFM blower (turbine) which effectively cools all critical components of the amplifier. The volume of cooling air far exceeds manufacturers' specifications for all critical components. The blower is positioned in such a way that it prevents hot air being circulated through the system. <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_DeH_ysJr0eM/S3B30hrAHEI/AAAAAAAAAf8/B0pH_1S_aEE/s1600-h/blower1.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://1.bp.blogspot.com/_DeH_ysJr0eM/S3B30hrAHEI/AAAAAAAAAf8/B0pH_1S_aEE/s400/blower1.jpg" alt="" id="BLOGGER_PHOTO_ID_5435976494511823938" border="0" /></a><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_DeH_ysJr0eM/S3B6U5xVmCI/AAAAAAAAAgM/ioVlnf6Cl4Q/s1600-h/DSC04111.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://3.bp.blogspot.com/_DeH_ysJr0eM/S3B6U5xVmCI/AAAAAAAAAgM/ioVlnf6Cl4Q/s400/DSC04111.jpg" alt="" id="BLOGGER_PHOTO_ID_5435979249759918114" border="0" /></a> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_DeH_ysJr0eM/S3B4Se3FZGI/AAAAAAAAAgE/UJ6JgQ463-o/s1600-h/blower.jpg"> </a><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_DeH_ysJr0eM/S3CLkXemLqI/AAAAAAAAAgs/62sXodJQnRw/s1600-h/sk-300a.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 260px;" src="http://2.bp.blogspot.com/_DeH_ysJr0eM/S3CLkXemLqI/AAAAAAAAAgs/62sXodJQnRw/s400/sk-300a.jpg" alt="" id="BLOGGER_PHOTO_ID_5435998207130087074" border="0" /></a> Eimac SK-300A and Y-309 Bypassed socket for the 4CX5000A/10000D/15000A... series tubes. <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_DeH_ysJr0eM/THZQp7wiN_I/AAAAAAAAAjk/CdhOqvbhwFI/s1600/sk-300a.2.jpg"><img style="display: block; margin: 0px auto 10px; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://2.bp.blogspot.com/_DeH_ysJr0eM/THZQp7wiN_I/AAAAAAAAAjk/CdhOqvbhwFI/s400/sk-300a.2.jpg" alt="" id="BLOGGER_PHOTO_ID_5509679875480500210" border="0" /></a> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_DeH_ysJr0eM/SDgABIJSe5I/AAAAAAAAAEY/BMx3xSSOEf8/s1600-h/4cx5000a-5-198.jpg"> </a> Front view of completed tank with air chimney in place.<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_DeH_ysJr0eM/SD8mwYJSfQI/AAAAAAAAAHQ/vrf9LBeNaUI/s1600-h/roller12.JPG"></a> <o:p> </o:p> <div style="text-align: justify;"><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_DeH_ysJr0eM/SDVfT4JSemI/AAAAAAAAABg/RnWxlHl4aDU/s1600-h/4cx5000a-5-191.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://1.bp.blogspot.com/_DeH_ysJr0eM/SDVfT4JSemI/AAAAAAAAABg/RnWxlHl4aDU/s400/4cx5000a-5-191.jpg" alt="" id="BLOGGER_PHOTO_ID_5203169739589974626" border="0" /></a></div> The picture above shows the typical Pi tank circuit configuration.<o:p></o:p> The plate tank circuit is a pi-network that matches the high impedance of the plate to the low impedance of the antenna. At the same time the circuit filters out undesired harmonics from the output signal. The signal from the plate enters through the .001 uf plate coupling capacitor. The 1000 pf 12,5kv plate tuning capacitor tunes the plate to resonance and the 2000 pf load capacitor (actually an assembly of switched fixed capacitors) adjusts the network for the best impedance match. If the plate tuning cap does not have enough capacitance the same method can be use to add capacitance.The tank coil consists of 45µH, a rolling inductor no need RF power switch.<o:p></o:p> can be seen in the photo.<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_DeH_ysJr0eM/SD8nRYJSfRI/AAAAAAAAAHY/HxDFb_nf8TI/s1600-h/roller11.JPG"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://1.bp.blogspot.com/_DeH_ysJr0eM/SD8nRYJSfRI/AAAAAAAAAHY/HxDFb_nf8TI/s400/roller11.JPG" alt="" id="BLOGGER_PHOTO_ID_5205922873756253458" border="0" /></a><meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style> Tuning: Keep eyes on the screen current while tuning the PA. The screen current will go drastically negative (-10mA) if the cavity is tuned too low in frequency.<meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><style>  </style>The Screen current must be + 1 to -1mA when tuned correctly. Adjust input and output tuners for maximum power.<o:p></o:p> <o:p></o:p><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_DeH_ysJr0eM/SDiPCYJSe6I/AAAAAAAAAEg/WToXZvIVzVA/s1600-h/4cx5000a-5-1929.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://2.bp.blogspot.com/_DeH_ysJr0eM/SDiPCYJSe6I/AAAAAAAAAEg/WToXZvIVzVA/s400/4cx5000a-5-1929.jpg" alt="" id="BLOGGER_PHOTO_ID_5204066640430529442" border="0" /></a> <o:p> </o:p> The blocking capacitors used were two pair of 1000pF attached to a copper strap that is copper soldered to the anode clamp. The coil side of the connection is to a copper plated brass plate, with the coil silver soldered to it. <o:p></o:p> An RF choke of 2.5mH is grounded to the chassis from the output terminal. This choke is for safety, should plate DC voltage ever appear on the tank circuit, the choke will short it to ground and cause the (HI VOLTAGE POWER SUPPLY<o:p></o:p>) to trip off-line. The choke also shunts to ground any static buildup on the antenna, and shorts it to ground when the amp is keyed into transmit.<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_DeH_ysJr0eM/SD8la4JSfPI/AAAAAAAAAHI/ZegzaW2-zEk/s1600-h/capacitor.JPG"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://3.bp.blogspot.com/_DeH_ysJr0eM/SD8la4JSfPI/AAAAAAAAAHI/ZegzaW2-zEk/s400/capacitor.JPG" alt="" id="BLOGGER_PHOTO_ID_5205920837941755122" border="0" /></a> <meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style><meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style>High-Voltage Power Supply.<meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style> High-Power RF Amplifiers High-Voltage, High-Current Power Supplies ….<o:p></o:p> One of the main items that is needed for a good amp is a good power supply.<div style="color: rgb(255, 0, 0);" align="center">These voltages can kill you... keep your hands OUT!</div><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_DeH_ysJr0eM/Sxuzj10GCfI/AAAAAAAAAd0/VrBW4VA8q34/s1600-h/transformer.3.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://3.bp.blogspot.com/_DeH_ysJr0eM/Sxuzj10GCfI/AAAAAAAAAd0/VrBW4VA8q34/s400/transformer.3.jpg" alt="" id="BLOGGER_PHOTO_ID_5412116805538154994" border="0" /></a><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_DeH_ysJr0eM/SxgQuC35GVI/AAAAAAAAAbc/IAnop0abC8k/s1600-h/transformer.5.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://4.bp.blogspot.com/_DeH_ysJr0eM/SxgQuC35GVI/AAAAAAAAAbc/IAnop0abC8k/s400/transformer.5.jpg" alt="" id="BLOGGER_PHOTO_ID_5411093335516977490" border="0" /></a><meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_DeH_ysJr0eM/Sxki2TWcb2I/AAAAAAAAAdE/5hzbLQcLztw/s1600-h/Homebrew+Transmitters+Logo.gif"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 394px; height: 43px;" src="http://1.bp.blogspot.com/_DeH_ysJr0eM/Sxki2TWcb2I/AAAAAAAAAdE/5hzbLQcLztw/s400/Homebrew+Transmitters+Logo.gif" alt="" id="BLOGGER_PHOTO_ID_5411394743565053794" border="0" /></a> HF BANDS QRP HI POWER LINEAR AMPLIFIER . An AM Transmitter Modification and Construction Project.<meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style> 1.6 - 30MHz (All Ham bands)<o:p></o:p> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_DeH_ysJr0eM/SxkHeAxwIlI/AAAAAAAAAb8/3m5MKR10Qvc/s1600-h/BIRD+4305A...jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 258px;" src="http://4.bp.blogspot.com/_DeH_ysJr0eM/SxkHeAxwIlI/AAAAAAAAAb8/3m5MKR10Qvc/s400/BIRD+4305A...jpg" alt="" id="BLOGGER_PHOTO_ID_5411364639448506962" border="0" /></a><a href="http://2.bp.blogspot.com/_DeH_ysJr0eM/TI08TvcgB7I/AAAAAAAAAlg/9ATuod1HKNU/s1600/hi+power+linear+amplifier.jpg"><img style="display: block; 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width: 400px; height: 300px;" src="http://4.bp.blogspot.com/_DeH_ysJr0eM/SxkMXze9KXI/AAAAAAAAAcM/OpHKgYU_nCA/s400/linear+amplifier.1.jpg" alt="" id="BLOGGER_PHOTO_ID_5411370030358931826" border="0" /></a> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_DeH_ysJr0eM/SxkMlxRy5-I/AAAAAAAAAcU/heD81imW7MU/s1600-h/linear+amplifier.2.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://1.bp.blogspot.com/_DeH_ysJr0eM/SxkMlxRy5-I/AAAAAAAAAcU/heD81imW7MU/s400/linear+amplifier.2.jpg" alt="" id="BLOGGER_PHOTO_ID_5411370270285031394" border="0" /></a><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_DeH_ysJr0eM/Sxkg9LEZqRI/AAAAAAAAAc0/uqWMu6cwhK8/s1600-h/linear+amplifier.4.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 396px;" src="http://1.bp.blogspot.com/_DeH_ysJr0eM/Sxkg9LEZqRI/AAAAAAAAAc0/uqWMu6cwhK8/s400/linear+amplifier.4.jpg" alt="" id="BLOGGER_PHOTO_ID_5411392662577719570" border="0" /></a><a href="http://2.bp.blogspot.com/-1Iu-67oP1MY/TjkxGIhuS1I/AAAAAAAAAqA/_FQWIMNUYxA/s1600/LINEAR1.jpg"><img style="display: block; margin: 0px auto 10px; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://2.bp.blogspot.com/-1Iu-67oP1MY/TjkxGIhuS1I/AAAAAAAAAqA/_FQWIMNUYxA/s400/LINEAR1.jpg" alt="" id="BLOGGER_PHOTO_ID_5636590390068792146" border="0" /></a> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_DeH_ysJr0eM/SxkbKr4IHFI/AAAAAAAAAcs/kt0ZIVeFkx0/s1600-h/ROLLER+1.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://2.bp.blogspot.com/_DeH_ysJr0eM/SxkbKr4IHFI/AAAAAAAAAcs/kt0ZIVeFkx0/s400/ROLLER+1.jpg" alt="" id="BLOGGER_PHOTO_ID_5411386297653140562" border="0" /></a><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_DeH_ysJr0eM/SxkhNexmN8I/AAAAAAAAAc8/VCFKJJ494Vo/s1600-h/linear+amplifier.5.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 363px;" src="http://3.bp.blogspot.com/_DeH_ysJr0eM/SxkhNexmN8I/AAAAAAAAAc8/VCFKJJ494Vo/s400/linear+amplifier.5.jpg" alt="" id="BLOGGER_PHOTO_ID_5411392942745466818" border="0" /></a><a href="http://3.bp.blogspot.com/-vQ-ASWP7JC8/TjkxhXhuSJI/AAAAAAAAAqI/DdMFzg1khXw/s1600/LINEAR.jpg"><img style="display: block; margin: 0px auto 10px; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://3.bp.blogspot.com/-vQ-ASWP7JC8/TjkxhXhuSJI/AAAAAAAAAqI/DdMFzg1khXw/s400/LINEAR.jpg" alt="" id="BLOGGER_PHOTO_ID_5636590857951791250" border="0" /></a> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_DeH_ysJr0eM/SxkoTCQya_I/AAAAAAAAAdU/J5VVqKRIouw/s1600-h/LINE+SECTION.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://2.bp.blogspot.com/_DeH_ysJr0eM/SxkoTCQya_I/AAAAAAAAAdU/J5VVqKRIouw/s400/LINE+SECTION.jpg" alt="" id="BLOGGER_PHOTO_ID_5411400734752271346" border="0" /></a><meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style> Line Section, 1-5/8" EIA Flange Single Element Socket - 4712-000<o:p></o:p> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_DeH_ysJr0eM/SxkogwkGUkI/AAAAAAAAAdc/ZSFwrGjvtqk/s1600-h/LINE+SECTION.2.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://1.bp.blogspot.com/_DeH_ysJr0eM/SxkogwkGUkI/AAAAAAAAAdc/ZSFwrGjvtqk/s400/LINE+SECTION.2.jpg" alt="" id="BLOGGER_PHOTO_ID_5411400970519597634" border="0" /></a> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_DeH_ysJr0eM/SxkQ_dHbtuI/AAAAAAAAAcc/ay-AB7vuwVk/s1600-h/linear+amplifier.3.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://4.bp.blogspot.com/_DeH_ysJr0eM/SxkQ_dHbtuI/AAAAAAAAAcc/ay-AB7vuwVk/s400/linear+amplifier.3.jpg" alt="" id="BLOGGER_PHOTO_ID_5411375109595969250" border="0" /></a><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_DeH_ysJr0eM/SxwYvIdEi0I/AAAAAAAAAeE/wTDrYf1FapU/s1600-h/bird+4712.00...jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://3.bp.blogspot.com/_DeH_ysJr0eM/SxwYvIdEi0I/AAAAAAAAAeE/wTDrYf1FapU/s400/bird+4712.00...jpg" alt="" id="BLOGGER_PHOTO_ID_5412228050194828098" border="0" /></a> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_DeH_ysJr0eM/Sxko1EPcHRI/AAAAAAAAAdk/hTUq9yZyiMA/s1600-h/LINE+SECTION.1.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://4.bp.blogspot.com/_DeH_ysJr0eM/Sxko1EPcHRI/AAAAAAAAAdk/hTUq9yZyiMA/s400/LINE+SECTION.1.jpg" alt="" id="BLOGGER_PHOTO_ID_5411401319399038226" border="0" /></a> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_DeH_ysJr0eM/SH0YPS3ibaI/AAAAAAAAAOM/pXD4rXgDBYk/s1600-h/pll+150watt.JPG"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://3.bp.blogspot.com/_DeH_ysJr0eM/SH0YPS3ibaI/AAAAAAAAAOM/pXD4rXgDBYk/s400/pll+150watt.JPG" alt="" id="BLOGGER_PHOTO_ID_5223357793861528994" border="0" /></a><meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style>AM PLL TRANSMITTER EXCITER 522-1800KHZ <o:p></o:p><meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><style>  </style>PLL Synthesizer Variable Power Output,swr Protection. The Best For Radio Station!!<o:p></o:p> <meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style> <style>  </style> <tr> </tr></tbody></table> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_DeH_ysJr0eM/SDVhWoJSetI/AAAAAAAAACY/StMGPo5dFVE/s1600-h/4cx5000a-5-196.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://4.bp.blogspot.com/_DeH_ysJr0eM/SDVhWoJSetI/AAAAAAAAACY/StMGPo5dFVE/s400/4cx5000a-5-196.jpg" alt="" id="BLOGGER_PHOTO_ID_5203171985857870546" border="0" /></a> The Classic Collins R-388A/URR (51j-4)HF communications receiver with Motorola andElectronic Assistance Corporation R-390A/URR. The 51J-4 is the predecessor to the R-390/URR and the improved R-390A/URR. The R-390A/URR, a military communications receiver built from 1955 to 1984, is still regarded as one of the best HF receivers around. Covering .5 to 32MHz in 32 bands and equipped with 26 vacuum tubes. Designed by Collins in 1955 as a low-cost replacement to it's predecessor, the R-390/URR, the R-390A/URR uses 26 tubes instead of it's predecessor's 32, and mechanical filters in place of crystal ones. My receivers R-390A was built not by Collins, but Motorola 1956 0014-PH-56 and Electronic Assistance Corporation ( 1967 DAABO5-67-C-0155 ). Over 55,000 R-390A receivers were manufactured by Collins, Motorola, Imperial, EAC, Teledyne, Stewart-Warner, Capehart, etc. from about 1954 to 1984. The 455 kHz IF utilizes crystal filters for 0.1 and 1 kHz bandwidths and mechanical filters for 2, 4, 8 and 16 kHz bandwidths. Operational capability of the receiver allows for remote control of the AGC and RF gain adjustments.<o:p></o:p> My R-390A is fairly complete, is in prety good shape, and works quite well. The R390A/URR is without question the best receiver (in my opinion) mass produced.<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_DeH_ysJr0eM/SD8igIJSfOI/AAAAAAAAAHA/vavjNjd68ro/s1600-h/r-390a1.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://4.bp.blogspot.com/_DeH_ysJr0eM/SD8igIJSfOI/AAAAAAAAAHA/vavjNjd68ro/s400/r-390a1.jpg" alt="" id="BLOGGER_PHOTO_ID_5205917629601184994" border="0" /></a><div align="center"> </div><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_DeH_ysJr0eM/SDVhWoJSeuI/AAAAAAAAACg/QwbpeRHMfRU/s1600-h/4cx5000a-5-197.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://4.bp.blogspot.com/_DeH_ysJr0eM/SDVhWoJSeuI/AAAAAAAAACg/QwbpeRHMfRU/s400/4cx5000a-5-197.jpg" alt="" id="BLOGGER_PHOTO_ID_5203171985857870562" border="0" /></a> Here are pictures of my Collins R-388/URR receiver. Collins Radio Company manufactured a lot of 51J3 and 51J4 receivers in the beginning of 1950's for the US Armed Forces, where they were called as R-388/URR and R-388A/URR. <o:p></o:p> This particular model receiver has a special place in my heart !!!! <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_DeH_ysJr0eM/SD6B4IJSfKI/AAAAAAAAAGg/84vlJrBXf58/s1600-h/r-388urr1.1.JPG"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://3.bp.blogspot.com/_DeH_ysJr0eM/SD6B4IJSfKI/AAAAAAAAAGg/84vlJrBXf58/s400/r-388urr1.1.JPG" alt="" id="BLOGGER_PHOTO_ID_5205741020545973410" border="0" /></a>I know Collins is a very respectable name in ham radio. Data plate of my Collins R-388/URR<o:p></o:p> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_DeH_ysJr0eM/SD6fhIJSfLI/AAAAAAAAAGo/p9GUKAdZOys/s1600-h/dada+plate+r-388.JPG"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://3.bp.blogspot.com/_DeH_ysJr0eM/SD6fhIJSfLI/AAAAAAAAAGo/p9GUKAdZOys/s400/dada+plate+r-388.JPG" alt="" id="BLOGGER_PHOTO_ID_5205773610757815474" border="0" /></a>and here you can see the s-meter of this receiver. The meter is calibrated in 20-,40-,60-,80-,and 100-db input signal levels and -10 to +6 db audio output level. <o:p> </o:p> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_DeH_ysJr0eM/SD6xcoJSfMI/AAAAAAAAAGw/49K91CDKE2E/s1600-h/DSC01650.JPG"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://1.bp.blogspot.com/_DeH_ysJr0eM/SD6xcoJSfMI/AAAAAAAAAGw/49K91CDKE2E/s400/DSC01650.JPG" alt="" id="BLOGGER_PHOTO_ID_5205793324657704130" border="0" /></a><o:p></o:p>This is the military version of the Collins 51J-3 communication receiver, Covering .5 to 30MHz, the R-388 has linear tuning over the entire frequency span. It is very stable and accurate utilizing the Collins 70E PTO. It features a built-in 100kc crystal calibration oscillator that can be compared directly against WWV.Checking dial calibration every 1/10-mc interrval throughout the tuning range .<o:p></o:p> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://1.bp.blogspot.com/_DeH_ysJr0eM/SDspPYJSe_I/AAAAAAAAAFI/FVIjVB5v5vs/s1600-h/r-388.1.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://1.bp.blogspot.com/_DeH_ysJr0eM/SDspPYJSe_I/AAAAAAAAAFI/FVIjVB5v5vs/s400/r-388.1.jpg" alt="" id="BLOGGER_PHOTO_ID_5204799138512927730" border="0" /></a>The R- 388/urr has a standard crystal filtering system. Only the 51J-4 version is equipped with the famous mechanical Collins IF filters, I consider the 3 and 6 kHz filters as very useful for AM reception, in some situations they are even better suited then the filters found in the R-390A.The receiver power supply can be operated from a 115 volt, 45 to 70 hz source and has provisions for 230 volt operation.<o:p></o:p> <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_DeH_ysJr0eM/SDx_RYJSfAI/AAAAAAAAAFQ/gCdwtmOQIk4/s1600-h/r-388.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://2.bp.blogspot.com/_DeH_ysJr0eM/SDx_RYJSfAI/AAAAAAAAAFQ/gCdwtmOQIk4/s400/r-388.jpg" alt="" id="BLOGGER_PHOTO_ID_5205175205849365506" border="0" /></a><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://3.bp.blogspot.com/_DeH_ysJr0eM/SD8pu4JSfSI/AAAAAAAAAHg/LDSe-WZO2X8/s1600-h/4444444444444.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="http://3.bp.blogspot.com/_DeH_ysJr0eM/SD8pu4JSfSI/AAAAAAAAAHg/LDSe-WZO2X8/s400/4444444444444.jpg" alt="" id="BLOGGER_PHOTO_ID_5205925579585649954" border="0" /></a>............................................................ 51J-4 <meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style><meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style> Collins R-392/URR Mobile Communications US Army Receiver.<o:p></o:p> Looking for some more photo of my R-392/URR military receiver. <meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style> The R392 is a communications receiver used by the US Army after 1954.<o:p></o:p> Range 0.5 to 32 MHz in 32 bands, AM/CW/MCW with BFO. <o:p></o:p>TM <a href="http://bama.edebris.com/download/military/r392/TM%2011-858.pdf">11-858.pdf</a> Instruction Book for Radio Receiver R-392/URR. 29 June 1954. <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_DeH_ysJr0eM/SwsHxdddSvI/AAAAAAAAAZ8/w2QlRm9BazU/s1600/R-392+RECEIVER2.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://4.bp.blogspot.com/_DeH_ysJr0eM/SwsHxdddSvI/AAAAAAAAAZ8/w2QlRm9BazU/s400/R-392+RECEIVER2.jpg" alt="" id="BLOGGER_PHOTO_ID_5407424323891579634" border="0" /></a> <meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><style>  </style>This unit was manufactured by Stewart Warner. A number of these units were manufactured by Collins. <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_DeH_ysJr0eM/SwsI8-JjhuI/AAAAAAAAAaU/mq6_zgBoIO0/s1600/R-392+RECEIVER.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 300px;" src="http://4.bp.blogspot.com/_DeH_ysJr0eM/SwsI8-JjhuI/AAAAAAAAAaU/mq6_zgBoIO0/s400/R-392+RECEIVER.jpg" alt="" id="BLOGGER_PHOTO_ID_5407425621156660962" border="0" /></a><meta equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5C1218%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link 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