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Message |
    
Wheelco505
Junior Member
Username: Wheelco505
Post Number: 26
Registered: 12-2004
| | Posted on Thursday, February 16, 2006 - 7:08 pm: | 
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i was looking at the parts list and it states that the 1446 transitors at 27-50 mhz are rated at 70 watts out p with 7 p watts in.that's what everybodys seems to live by, and when somebody says they got more watts out of them,people say NO WAY!! okay,well on the same page it says that:at 14-30 mhz cb/amateur 90 watts p out and 5 watts p in. both include the cb band.i would like to know the forums view on this.i'am sure there's going to be an explaination ,because nobody's going to let those guy's that say they got those 90 watts out of those transitors in the palomar 600,beat there chest.but i'am just saying what rf parts say.since they are always quoted in this matter.so forum members it would be nice to hear your views. 505 |
Bruce
Senior Member
Username: Bruce
Post Number: 3558
Registered: 9-2003
| | Posted on Friday, February 17, 2006 - 6:50 am: |
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505 i can get 500 watts out of a 1446 in pules mode however the life of the part will be extreamly short.
Basic rules on output are CCS and ICAS the CCS is what it will run safely all day and the ICAS is normaly 30-50% transmit
Most parts are rated at a safe output ( CCS ) and with good harmonic output levels ...... as you go up the level of harmonics goes through the roof and you see lots more output but much of it is junk.
Back in the 60's WW2 tubes were very cheep and the 807 and 829 cost 1-2 bucks both were good for 100 watts ....... we used to say on the 829 you could tell you had it right when you could see the white hot grid glowing through the red hot plate ...... Today its 1446 transistors however if you see it glowing red its too late ........ |
Wheelco505
Junior Member
Username: Wheelco505
Post Number: 27
Registered: 12-2004
| | Posted on Friday, February 17, 2006 - 2:04 pm: |
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hey bruce!! that's a rich joke ha!! ha ha!! about the glowing red!!even my wife who looks over my shoulder fell in the floor laughing!!but i see what you are saying,you can have a certain amount of watts on the meter, but does'nt mean all those watts are clean. 505 |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2424
Registered: 7-2004
| | Posted on Friday, February 17, 2006 - 6:47 pm: |
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i spoke to rf parts a while ago regarding the 2 ratings. the tech dept felt the 70 watt rating was where the 1446's worked best. the 90 watt rating & its associated circuitry was not conducent to clean, quality 11m rf power. |
Bruce
Senior Member
Username: Bruce
Post Number: 3561
Registered: 9-2003
| | Posted on Friday, February 17, 2006 - 6:53 pm: |
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The tube story is TRUE ..... Back then I had 10 - 20 829b's at any time here and running them on 2 meters ( AM ) at a cool temp got you 45 - 60 watts out however you could run them HOT with a fan blowing on them ...... YES you could see the grid getting HOT and the plate glowing RED and get 100 watts out but the tube life was ZIP ......... Maby a week and it was toast.
The 829b was designed as a VHF Aircraft transmiting tube in the mid 1930's and to today is STILL a good 6 and 2 meter 60 - 100 watt amp after 70 years but WAY too much money for what you would get out of one..
The 832 tube was a 15-40 watt ver of this tube and again very widely used new tubes like the 6360 and 2E26 grew out of this line of tubes.
The 807 tube ( 1625 ) was a 1930's 6146 very common in WW2 surplus and like the 829 VERY CHEEP. Look at most 1950's heath kits like the DX-100 and you will see 807, 1625 or 6146 tubes
Common WW2 radios SCR-522, ARC-3 ARC-5 ( VHF ) were widely converted by young hams like myself in the 50's 60's.
Today we look at thoes and go WOW all of that for a few watts! |
Wheelco505
Junior Member
Username: Wheelco505
Post Number: 29
Registered: 12-2004
| | Posted on Saturday, February 18, 2006 - 12:21 pm: |
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hey patzerozero!!you saw it too,i now know that i was not crazy!i thought it was a typo at first on the rf parts site.but now i have to go back to friends who have these "hot boxes", and apologize for calling them liars when they keep saying(and showing me)that they are getting 500-600 watts out of these boxes.even though they are not clean watts but highly over driven watts. (i might add they use 3 fans i guess i know why huh!) 505 |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2435
Registered: 7-2004
| | Posted on Saturday, February 18, 2006 - 3:07 pm: |
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have 'em put a TVI filter on those 150 watt 1446's & watch the output DROP to 75 watts, more where it should be! another way to check for inefficiency is see how much swing shows on the RMS/AVG scale vs PEP. the 1446's, efficiently MAY show 40-50 RMS swing, & 75 PEP swing. inefficiently, they'll still show around 50 RMS swing & 150 PEP. (not really accurate measurements, but it'll show roughly when the PEP is nothing more then trash). once the RMS swing ceases to increase, there is reason to increase PEP swing.
also depends on what box is running 'em & at how many volts. even commercially made boxes can will show a few more watts at 14.5 vs 12 volts, & a lot of manufacturers(especially the custom builders) rate at 15 volts as the 'standard'. unless you have a maul or re-regulated alternator, your mobile is only getting 'near' 14 volts tops, depending on how long you key, battery capacity, alternator performance, etc. on a normal power supply, even if it varies up to 15 volts, once you key it, it probably drops back down to under 14 anyway, no matter what the meter may say. |
