| Author |
Message |
    
Rosco
| | Posted on Monday, June 03, 2002 - 2:18 am: | 
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Got my new moonrakers 4 installed on my 34' tower with a 10 foot mask. Standing wave under 1.5 both verticle, horizontal. Problem KLV 350 will key but , somtimes will chatter, and or just wont unkey at all. Works great on Antron 99, with galaxy melaka, I have a three way antenna switch box, I made all new coax jumper's all different lengths, tower is grounded with 8 foot copper rod. Like I said every thing is great with antron and klv, but not on moonraker 4 beams. Any help suggestions appreciated : Thanks Rosco, rosco@tctc.com |
Marconi
| | Posted on Monday, June 03, 2002 - 11:20 am: |
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Rosco, if you have an SWR meter in your radio, check the SWR between the radio and the amp using both antennas. You can use your SWR results, but once I set the meter using the standard antenna, I prefer to watch the set value readings of the meter to indicate the differerences between the antennas. You should see an insignificant difference in these values if the antennas are presenting similar loads.
For this to really have meaning, you should make this type of comparison using a non-reactive dummy load. In this case or without a dummy load, the A99 will have to serve as the comparative standard here.
If you have to add a meter in line, understand that by adding a jumper and a meter you will likely change the feed line relationship between the TX and the amp some, but this will at least give you a reference point to use to play with your jumper lengths in order to find a combination that stops the amp from acting up. The exercise may also give you some understanding of line affects on feeding an amp without a tunable input.
Of course the best thing to do is to try and fix the moonraker tune to the true resonance you are looking for. You may see a good SWR were you are but you probably have not tuned out the reactances as well as you could. Gamma matches can be difficult at times.
Of course it could be your amp, but then why does the A99 work OK?
Do you know how broadbanded, below 2:1 SWR, your
MR'r is at this point. That may suggest something about your present tune, if it is too broad.
Just something to consider,
Marconi |
USA194
| | Posted on Monday, June 03, 2002 - 1:51 pm: |
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There is something about the KLV-350 keying circuit which makes it quite susceptible to chattering. It seems to be either something with the capacitance at the radio connector OR the keying circuit is set WAAYYY too sensitive OR the tubes are not properly neutralized or biased and causing a "feedback" situation. I had the same problem with a KLV chattering on a Comanche Warrior, but not on a Superbase. The fix was to change the jumper length between radio and amp. Also, I removed that entire PCB where the little inhibitor chip sits.
NOW..with that said, you might investigate the possibility of changing the input level required to trigger the amp(note that the KLV series is designed to be operated with between 1-10 watts, which seems awfully sensitive to me for AM) |
Taz
| | Posted on Monday, June 03, 2002 - 2:28 pm: |
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Those moonraker 4's are great. I just put mine up and heck your running the same setup I am basicly.
Once you get the swr right you will be set. Just tighten it all down and have fun.
Taz |
Rosco
| | Posted on Tuesday, June 04, 2002 - 8:19 pm: |
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A thank you for all who responded to my help, problem. I did a few coax inspections, and found one that had a bad ground. Now I can use the klv 350 on beam, but can only get it to do about 100 watts, before the 350 starts wont unkey and or chatters. It is possible that I have the problem
at the beam connections. Thank you all very much. Rosco 308. Indiana Bob T. |
Taz
| | Posted on Tuesday, June 04, 2002 - 9:35 pm: |
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do you mean like at the connection bracket where the coax screws in? Maybe the gamma rods? |
Rosco
| | Posted on Wednesday, June 05, 2002 - 8:17 pm: |
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Problem Solved. KLV 350 would not unkey and or would jatter while on moonraker beams. My solution seemded to fix the problem. Trial and error with different lenght jumper's till able to obtain very same SWR on ch. 1 and ch. 40 which was 1.6 and on ch. 20 1.5, this fixed my problem, and now able to use KLV 350 both low and high peaked power !!! and have no problems. Thanks to all who responded. rosco 308 Indiana Bob T. |
Kirk
| | Posted on Friday, June 07, 2002 - 10:51 pm: |
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your problem is an age old one my friend...RF in the shack. changing your jumper solved it, but just so you know...RF coming back down the pipe or being present in some fashion (i.e. front end overload maybe??) did it. |
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