Re: [Drakelist] L4-B on AM
While I don't use my L4 on AM, I do use it for contesting. I use two muffin fans sitting on the top of the cabinet, one directly over each tube. These are the lower speed fans so they are fairly quiet but they still do a great job of providing additional cooling. They are positioned to blow the warm air up. 73, Stew K3ND From: K9sqg k9...@aol.com To: d...@martineer.net; k7...@comcast.net; drakelist@zerobeat.net Sent: Monday, August 15, 2011 12:12 AM Subject: Re: [Drakelist] L4-B on AM At one time, there seemed to be great interest in the L-4B because it could run 1 kw input on CW, RTTY, and AM. A lot of other amps were rated at, for example 1,500 watts input on SSB but maybe only 700 or so on AM because they didn't have power supplies, cooling, etc. for continuous duty or high duty cycle modes. I'm sure there are some users out there, maybe on some of the AM nets, that have direct experience. Note, however, the top of the cabinet, especially over the tubes, gets quite warm in such applications... -Original Message- From: Don Cunningham d...@martineer.net To: jsloss k7...@comcast.net; drakelist drakelist@zerobeat.net Sent: Sun, Aug 14, 2011 8:08 pm Subject: Re: [Drakelist] L4-B on AM I too would be interested in the L4B's performance/use on AM. I may use the DX-60 or T4XC as the driver, but same question, hi. 73, Don, WB5HAK ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] L4-B on AM
On 2011-08-15, at 12:05 AM, Don Cunningham wrote: I too would be interested in the L4B's performance/use on AM. I may use the DX-60 or T4XC as the driver, but same question, hi. 73, Don, WB5HAK ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist Hi Guys, A good rule of thumb to follow when using any LINEAR amplifier for AM fone is simply this: the MAXIMUM carrier output power obtainable out of it is equal to the plate dissipation power of your final tubes divided by two... Example: I use a pair of paralleled 813 tubes in my HB amplifier---each tube has a plate dissipation of 125-watts, giving me a TOTAL dissipation of 250-watts. The most AM carrier output I can expect to get out of my set-up is 2 x 125 = 250-watts DIVIDED by 2 = 125-watts. Adjust your drive until such time as the correct power output from the amplifier is obtained---then tweak the plate tuning control of the amp one final time for maximum output (it will be minimal)... This is the very set-up I used for years here at VE3CUI, using a HB AM transmitter as an exciter...the output from the exciter was some 10-12 watts, or so, I got 125-watts out of the 813s---a VERY worthwhile boost in my station's AM performance...! ~73~ de Eddy VE3CUI - VE3XZ ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] L4-B on AM
If you are going to use the L4B with the T4XC or Heath DX 60 both use controlled carrier AM phone. This method will be very close to SSB as far as the L4B is concerned and I would use it in the same manner as any SSB rig. Good reports have been received using the T4XC in the AM mode. Remember to adjust the audio properly as their is no AGC action on the T4XC when in the AM mode. As far as using the L4B with a Typical plate modulated rig, I would not wast the time. Any AM rig, or most run 100 watts or 400 watts peak envelope power. Using the L4B would only ad marginally to this amount. Even if driven by a 50 watt Johnson Ranger the signal at the received end wold not be much different then the barefoot Ranger. That is say 200 watts pep from the just the Ranger to 500 watts as an example from the L4B, this is a difference of 4db and just noticeable at the receive end. 73 Tim WB8UHZ From: Eddy Swynar deswy...@xplornet.ca To: Don Cunningham d...@martineer.net Cc: drakelist@zerobeat.net Sent: Monday, August 15, 2011 7:47 AM Subject: Re: [Drakelist] L4-B on AM On 2011-08-15, at 12:05 AM, Don Cunningham wrote: I too would be interested in the L4B's performance/use on AM. I may use the DX-60 or T4XC as the driver, but same question, hi. 73, Don, WB5HAK___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist Hi Guys, A good rule of thumb to follow when using any LINEAR amplifier for AM fone is simply this: the MAXIMUM carrier output power obtainable out of it is equal to the plate dissipation power of your final tubes divided by two... Example: I use a pair of paralleled 813 tubes in my HB amplifier---each tube has a plate dissipation of 125-watts, giving me a TOTAL dissipation of 250-watts. The most AM carrier output I can expect to get out of my set-up is 2 x 125 = 250-watts DIVIDED by 2 = 125-watts. Adjust your drive until such time as the correct power output from the amplifier is obtained---then tweak the plate tuning control of the amp one final time for maximum output (it will be minimal)... This is the very set-up I used for years here at VE3CUI, using a HB AM transmitter as an exciter...the output from the exciter was some 10-12 watts, or so, I got 125-watts out of the 813s---a VERY worthwhile boost in my station's AM performance...! ~73~ de Eddy VE3CUI - VE3XZ ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] L4-B on AM
Thanks Tim and others for the excellent descriptions. That was what my old mind and reading and re-reading the manuals told me would work. I have a nice Johnson Viking II that I will use for plate modulated AMing, and don't plan to amplify what it can do, I also know to modify the DX-60 to control the output betterand modify for PTT before using it with the L4B. I have the information to do that right after I change the electrolytics that look original, hi. Thanks again to all, Don, WB5HAK___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] L4-B on AM
I put two on the power supply too. 73, Lee -Original Message- From: GALE STEWARD k...@yahoo.com To: K9sqg k9...@aol.com; Drake Reflector drakelist@zerobeat.net Sent: Mon, Aug 15, 2011 7:30 am Subject: Re: [Drakelist] L4-B on AM While I don't use my L4 on AM, I do use it for contesting. I use two muffin fans sitting on the top of the cabinet, one directly over each tube. These are the lower speed fans so they are fairly quiet but they still do a great job of providing additional cooling. They are positioned to blow the warm air up. 73, Stew K3ND From: K9sqg k9...@aol.com To: d...@martineer.net; k7...@comcast.net; drakelist@zerobeat.net Sent: Monday, August 15, 2011 12:12 AM Subject: Re: [Drakelist] L4-B on AM At one time, there seemed to be great interest in the L-4B because it could run 1 kw input on CW, RTTY, and AM. A lot of other amps were rated at, for example 1,500 watts input on SSB but maybe only 700 or so on AM because they didn't have power supplies, cooling, etc. for continuous duty or high duty cycle modes. I'm sure there are some users out there, maybe on some of the AM nets, that have direct experience. Note, however, the top of the cabinet, especially over the tubes, gets quite warm in such applications... -Original Message- From: Don Cunningham d...@martineer.net To: jsloss k7...@comcast.net; drakelist drakelist@zerobeat.net Sent: Sun, Aug 14, 2011 8:08 pm Subject: Re: [Drakelist] L4-B on AM I too would be interested in the L4B's performance/use on AM. I may use the DX-60 or T4XC as the driver, but same question, hi. 73, Don, WB5HAK ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] L4-B on AM
Has anyone used their L4B as an amplifier being driven by a 30-40W output plate modulated rig (ie AF-67 etc). Your comments on results, power output etc will be appreciated. The L-4B normally follows a C-line; this is just a little extra choir for it. Thank you. Joe k7mks___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] L4-B on AM
I too would be interested in the L4B's performance/use on AM. I may use the DX-60 or T4XC as the driver, but same question, hi. 73, Don, WB5HAK___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] L4-B on AM
At one time, there seemed to be great interest in the L-4B because it could run 1 kw input on CW, RTTY, and AM. A lot of other amps were rated at, for example 1,500 watts input on SSB but maybe only 700 or so on AM because they didn't have power supplies, cooling, etc. for continuous duty or high duty cycle modes. I'm sure there are some users out there, maybe on some of the AM nets, that have direct experience. Note, however, the top of the cabinet, especially over the tubes, gets quite warm in such applications... -Original Message- From: Don Cunningham d...@martineer.net To: jsloss k7...@comcast.net; drakelist drakelist@zerobeat.net Sent: Sun, Aug 14, 2011 8:08 pm Subject: Re: [Drakelist] L4-B on AM I too would be interested in the L4B's performance/use on AM. I may use the DX-60 or T4XC as the driver, but same question, hi. 73, Don, WB5HAK ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
