开云体育

Single Messages Topics Expanded Polls

Re: 6 meter output

Dennis All Messages By This Member #400 Hobart, ?? I'm a little unclear from your email about the duty cycle you're running to get those temps. To answer your first question; the "key down on 120V" is limited first by power supply current draw.? (on 120 the amperage is twice that of 240)? So 1kw on 120 would cause the amp to cut out in about 1/2-second.?? You should be able to run indefinitely on SSB, 120V, without getting close to exceeding any limits with a stout 120V circuit.?? The power supply electrolytics will hold the supply voltage up fine on SSB AS LONG AS the 120 voltage holds up to around 120/125, but if it's a weak circuit the voltage will drop considerably (10 to 15V) which will cause the amp to Current Fault off. ? The amp faults off due to excessive KEY DOWN current at or just below 1kw on a 120V circuit.? That shut-down mode is not due to temperature, but from the amperage going IN to the power supply. ?? Having said that, if you're really "hammering" it with audio (processor on, mic gain set too high) you could cause a current fault on 120V.? In normal SSB you should be able to run indefinitely without over-temping the amplifier regardless of supply voltage. ?? If your supply power is 240 or a really hot and strong 125v, it will do 1kw key down for maybe two minutes before getting too hot.? Palstar's recommendation about 1kw being too much on 120 is sound advice.? The fact is that most 120V circuits in houses aren't robust enough to supply the current without excessive line-voltage drop causing the power fault. Again, long-term "key down" time is limited by temperature, not supply voltage.? If your supply voltage is soft, it will fault off in less than a second.? If it stays on beyond that, then you become temp limited.? The time to reach temp limit time is determined by several things... 1) ambient temperature 2) altitude (air density) 3) band of operation, higher frequencies tend to be more efficient since less heat is generated. ?73, Dennis toggle quoted message Show quoted text On 7/1/2020 at 11:19 AM, "Chris E." <kc2rgw@...> wrote: I'm curious what you are running that runs that long at that high a duty cycle to drive the temp like that? I run digital modes, things like PSK-31, JS8, Olivia, packet, Thor and for that I typically just run maybe 200W max due to duty cycle and definitely run transmissions that run for several minutes at a cycle but amp draw (amp indicated, believe it's the 50V supply reading)? is <12 when I run at that power level and temp stays generally 65 or lower.? In my case I'm on 240V. For phone on SSB the temps are much lower when I'm running 800W (based on carrier tune to set drive level) or so output because voice is so much lower duty cycle. I've not seen temps with normal SSB voice even at 1kW output get much over 65C with fairly windy overs. On Wed, Jul 1, 2020 at 12:37 PM Hobart Poyser <hobart1943@...> wrote: How long can you key down your 1K output on 120VAC? When moving my shack to the house I put in 3 brand 120VAC circuits plus one 220VAC circuit later after finding a 5 minute Key down SSB period would give me 1K on 120 for less than a minute, then around 650 for?another minute or so before it shut down due to reaching 100C. Please advise how long can you get 1K "keydown" with 120VAC? We would all like to know.? Palstar engineering does not recommend input to amp to get 1K out on 120VAC. Just my 2 cents and 3 cents worth of experience. Who knows maybe I don't know how to read meters after 40 years in the hobby, KR9G On Tue, Jun 30, 2020 at 8:00 AM Dennis via <pegasus9000@...> wrote: Back to the "Six meter output" subject first.... ??? This amp is VERY efficient on 6 meters... around 72% is what I measured here on two of them.?? What this means is that you will easily get 1kw of output on 6-meters SSB with a stout 120v supply voltage.? I wouldn't be surprised if you could do CW or FM at 1 kw.?? This assumes you have a good stout 12vac main circuit.? A whimpy one with a long run of small wire won't cut it, but something up to code should work fine.? These LDMOS devices really start to "sing" at VHF so their efficiency is way up by 50mhz as opposed to mid to low 50s at HF so the demands on the AC line are much less there. ?? The "Pure Signal" jack is for very modern transceivers which employ a circuit that cuts transmit IMD by about 20 or 30db.?? It basically takes a sample of the transmitted signal from your amp via that Pure Signal port, feeds it back to the transceiver which instantly generates a signal 180-degrees out of phase to cancel the undesired IMD out of your passband.? Pretty much the only radio that commonly does this are the various Anan models. ?? Congrats on ordering one, both of mine work well. Dennis N0SP On 6/29/2020 at 9:31 PM, "Steve Shep" <shepsvettes@...> wrote: Also what is the pure signal jack for. -- 73? de?Chris?-- KC2RGW ------------------------------------------------------------ ˙dn ?p?s ????? ?o??uo? ?no? u?n? ?s???d 's??? ?u?p??? ??? no? ??

View All 27 Messages

#400

Join [email protected] to automatically receive all group messages.