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Message |
    
Itatorro
Junior Member
Username: Itatorro
Post Number: 28
Registered: 6-2005
| | Posted on Tuesday, June 21, 2005 - 8:46 am: | 
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I post this in Ask the Tech but have no response.
What amps seem to be most forgiving to Higher SWR?
I understand that Magforce suggest that you have no higher than 1.4 and lower is even better for amps longevity. In most antenna systems 1.4 is considered very good. I currently run a SS102 whip and have about 1.35 SWR and cant get better. When driving the SWR will vary some I am sure higher than 1.4 spikes would occur.
I would like to keep this thread on Subject please.
I am not into comp so i want the most trouble free instal as possible.
Current amp choices: Not in order.
TS DX500V
TS DX1600 future pwr available
Magna 600
Magna 350
Will be running with M257 coming in this week
possible S-9 in future
Current system: Cobra 75 Laugh if you will, KL400 DK 50w swing 80w
All RG58. 8’ jumper, 13’ to antenna……
Some will say that the KL is fine and I agree. I consider the KL400 disposable and I would like to have a NO sweat power in the range of 150-200w DK with 500-600w PEP……
Thank you, Forum Members.
It
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Bruce
Senior Member
Username: Bruce
Post Number: 2875
Registered: 9-2003
| | Posted on Tuesday, June 21, 2005 - 10:04 am: |
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1.4 / 1 is a 97% effective system it would seem to me that a good amp should work over a much wider range ... more like a 2 / 1 match |
Tech808
Moderator
Username: Tech808
Post Number: 6141
Registered: 8-2002
| | Posted on Tuesday, June 21, 2005 - 1:55 pm: |
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Itatorro,
If your highest SWR reading is at a 1.4 across the band you really should not have any problem's running any amplifier with your setup.
Lon
Tech808
CEF808
N9OSN
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Itatorro
Junior Member
Username: Itatorro
Post Number: 30
Registered: 6-2005
| | Posted on Tuesday, June 21, 2005 - 2:31 pm: |
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Thank you Tech808
Now, with my new Copper Tuned M257. wich of the amps in my list above would give me the real no sweat Watts that i am looking for?
Also, I found out my jeep has a 117amp alt that DC considers Heavy duty. Would this support the power that i seek?
thank you all,
it |
Tech808
Moderator
Username: Tech808
Post Number: 6144
Registered: 8-2002
| | Posted on Tuesday, June 21, 2005 - 2:43 pm: |
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Itatorro,
My Personal choice from the Amps that you listed above would be the TS DX500V
Texas Star DX 500V Mobile
Hope this help's,
Lon
Tech808
CEF808
N9OSN
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Alsworld
Advanced Member
Username: Alsworld
Post Number: 927
Registered: 1-2002
| | Posted on Tuesday, June 21, 2005 - 10:41 pm: |
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Itatorro,
your SWR's are fine for any amplifier. The reason you see the MagnaForce calling for such a low SWR is that in those line of amps (X-Force, Magna Force, Dave made, etc) are all competition amps. Most who run them are going for max power driving them hard, many times with one amp driving another squeezing every last watt out of them (many times volted more than stock 13.8 volts). These amps can give and give the power for extended keydowns, provided a high SWR doesn't damage them with reflected power. Hence the recommendation of a best case SWR scenario. If you just plan on driving one amp with your radio and not competing, your SWR's are great. Purchase any amp with confidence.
I did notice your 400 DK 50 swinging 80 watts. I must assume that is RMS watts?
Alsworld |
Itatorro
Junior Member
Username: Itatorro
Post Number: 31
Registered: 6-2005
| | Posted on Wednesday, June 22, 2005 - 7:40 pm: |
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Thnks Alsworld:
those readings were from a RATShack meter set in PK mode. The Scale is hard to read as I only had the 200w scale to choose from with this pwr level...
I used a Bird43 to get my SWR numbers and plugged them into my spread sheet at work.
Believe it or not the RS Meter(SWR mode) gave me an accuracy within .5 of the Bird numbers.
I got my A-1700 antenna today and went to adjust it and found something interesting. I think i need to post this new ?? in a different thread, will be looking for the correct place to put it very soon.
it.
Heres a short version: SWR- 1.25 across band until i get above 90watts out then it is into the Strawberry Zone. 2.7-3+: 1...... |
Iluvrf
Intermediate Member
Username: Iluvrf
Post Number: 138
Registered: 2-2005
| | Posted on Thursday, June 23, 2005 - 6:48 am: |
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Radio shack SWR meters are pretty accurate. Most all swr meters, for that fact, are pretty accurate |
Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 968
Registered: 7-2004
| | Posted on Friday, June 24, 2005 - 7:34 pm: |
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like alsworld says, itatorro, the custom/competition amps are built to wring every single last watt out of each transistor & when you run 'em like that they are already pushed to their limits. stressing them further with 'high' swr's/reflected watts just helps to reduce their life. when 'loafing' as opposed to being hammered, 2:1 swr's will not damage the transistors 'immediately', like overdriving & high swr's could. ran texas star 250/350 in boats with swr's 2.5:1, sure reflected was high but those amps still perform flawlessly today. |
Hotwire
Intermediate Member
Username: Hotwire
Post Number: 442
Registered: 1-2005
| | Posted on Tuesday, July 19, 2005 - 10:43 am: |
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I have a cheapo Galaxy 225 in the mobile. I have a 2 watt dead key and a 20 watt swing from a cobra 148. My vswr with amp off is 1.1, with amp on its about 2.5!!! I run that little dude full power for about a year now EVERYDAY! Have had no problems what so ever. I do have my amp mounted right in front of my AC vents to keep it cool at all times because a 20 watt swing really heats it up. Nice winter hand warmer. |
