| Author |
Message |
    
Ca346
| | Posted on Saturday, October 18, 2003 - 9:57 pm: | 
|
I decided to post this in the base Radio section. Sure hope it's the right place?
I have two radios in my base station: ICOM706MKIIG, Ham radio and a President HR2510. The ICOM is straight to a MFJ tuner then to a low pass filter and out to two antenna's through a switch. Bare bones 100W.
The President also goes through the tuner, but through a Galaxy350 amp first. Usually about 175W. I tried it without the amp, but it's still the same SWR situation described below.
If I tune either radio down to 1:1 on the MFJ-969, and then later switch radio's to transmit, the SWR is always too high. Either way I start it's high on one and flat and the other.
Is the radio causing the reaction? |
Tech808
| | Posted on Sunday, October 19, 2003 - 12:17 am: |
|
CA346,
On my MFJ 989C / Versa Tuner V it does the same thing.
When I switch from radio to radio I always have to re-adjust the 989C
I know this is not much help, but thought I would let you know I run into the same thing.
I also run all of the radios thru a MFJ 1700B Transmitter/Antenna switch which allows me to have up to 6 Radio's & 6 Antennas hooked up at a time.
Maybe Tech307 or Tech833 can offer better advice, as to if this is normal.
Lon
Tech808 |
Kc0gxz
| | Posted on Sunday, October 19, 2003 - 1:04 am: |
|
Ca346
I'm curious to know what kind of antenna you are running that requires a tuner.
If I wanted to get a true comparison between the two radios, I would do it this way.
First of all, into a dummy load, tune your Icom down the the same wattage output that your 2510 has. That way you know that you're dealing with pretty much the RF for both radios.
If you are using a CB base antenna, disconnect everything in line between the radio and antenna "except" the SWR meter.
Now do the SWR/radio comparison. Two radios of equal power should show the same SWR within two to three points. If even that much.
If you are using the SWR meter in the tuner, make very sure that you are in the "Tuner Bypass" posistion when Comparing the SWR of each radio.
You didn't mention what path after the amplifier that the 2510 takes. If the two radios do not follow the same path, then I can understand why you are getting two different SWR readings.
Personally, I have never seen the same SWR reading from a radio that was reading it at 10 watts and then at 150+ watts. A lot of strange things are happening between 10 and 150 watts.
Anyways, try the above and see how close they are then.
73 Jim.
Jeff, kc0gxz. |
Pig040
| | Posted on Sunday, October 19, 2003 - 10:07 am: |
|
Ca346,
I have a Kenwood 850Sat, and a Yaesu 101, use the same antenna, switchbox, for both, and the 850 shows a lower swr on the beam, but the 101 shows a lower swr on the vertical?? Just radio idiosyncracies I think. Who knows.
Had the same in the mobile, My galaxy 99 showed a lot higher swr than my connex?? I think it is just the radio gnomes!! Or maybe the aliens down here in roswell, lol |
Kc0gxz
| | Posted on Sunday, October 19, 2003 - 12:48 pm: |
|
Pig040
I thought the alien problem down in Roswell was taken care of.
Jeff. |
Ca346
| | Posted on Sunday, October 19, 2003 - 9:49 pm: |
|
I'm going to look closer at this tomorrow (Monday). As I am writing this, it's time for 60 Minutes...... Thanks for the feedback.
My two antenna's are: GAP VIII (Vertical) I tune the 10M Band into 11M.
Lightning 4+ Quad dual polarization. Using the vertical against vertical. BUT... Been thinking about the HR2510 and the built in SWR Meter adjustment.... |
Ca346
| | Posted on Sunday, October 19, 2003 - 10:27 pm: |
|
60 Minutes wasn't any good. Don't watch baseball (I know, I know).
I tested the two radio's as suggested by Kc0gxz, Jeff. You are right on.
When I dropped the power on the ICOM to match the HR2510 (20W SSB), it matched. Only when I increased the power on the ICOM did the SWR go back up and need retuning.
The same thing happened when I went the other way through the HR2510 with and without the amp. Fine until I turned on the amp.
I also remembered that because the HR2510 has an internal SWR adjustment, I was not comparing apples to apples. Incidentally, the Lightning 4+ has two seperate coax cables for the horiz/vert choices. The adjustment on the SWR on the ground (ladder) was flat, but sitting at 50 ft. it's not the same for either choice. So even changing from vertical to horizontal I have to retune. I'm not real excited about climbing the tower to adjust it. I do have a harness, but I would have to climb up and down a few times to adjust the brass wires used for the transmatch system.
Thanks alot guys. As usual, I learned alot from the forum input. |
Pig040
| | Posted on Monday, October 20, 2003 - 10:25 am: |
|
Jeff,
If you want to watch something interesting, Wednesday night is the night most alien sightings are made. I dont know if the aliens are just trying to beat the boredom of hump day, or if the people who sighted them were having a few trying to beat hump day! Lots of wierd sightings, still. Roswell has the largest regional airport, capable of taking jumbos, and no big comercial flights come in, some say due to secret goverment stuff. I know I have seen several stealth fighters, and bombers, and some fighters I cant identify going in there. Who knows what uncle sam has hidden away! |
Kc0gxz
| | Posted on Monday, October 20, 2003 - 1:15 pm: |
|
Pig040
Out of curiousity, how close can you get the stealths and other bombers?
And have you-yourself seen strange things going on out there in the desert that have made the hair stand up on the back of your neck?
Jeff. |
Ca346
| | Posted on Monday, October 20, 2003 - 10:58 pm: |
|
If you want to listen to them, check out
"http://members.tripod.com/columbus_east/area51.shtml"
Jim
CA346/CEF197
|
Pig040
| | Posted on Tuesday, October 21, 2003 - 10:14 am: |
|
Jeff,
The airport in Roswell is an old military base, and you can set there and watch all kinds of stuff land. There are a lot of commericial aircraft half torn apart, in town they have the nose pieces of big jets for sale, those suckers are stood up, and they are about 30feet high! We went out into the desert one night, and sat on the truck and could see lots of things flying around that were, in my opinion not explainable. When you ask someone who has lived their whole lives down here, they talk about wierd flying things as matter of fact, not open for debate! |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 111
Registered: 7-2004
| | Posted on Sunday, August 08, 2004 - 10:04 pm: |
|
I have a similar situation in mt two radios. It might be that one is a high powered radio, but I havev a Cobra 148 GTL that is doing 2.5 watts dead key, and an SWR well under 1.5.1. I also have an RCI 2970 DX that dead keys at about 30 watts, but the SWR is 2.0.1. Is this simply because of the power difference? THe built in SWR meter on the RCI shows 4 bars and gets hot even on low power after talking for awhile. |
Bruce
Senior Member
Username: Bruce
Post Number: 1442
Registered: 9-2003
| | Posted on Monday, August 09, 2004 - 4:23 am: |
|
the swr should be the same UNLESS your ranger is putting out junk |
Highlander
Advanced Member
Username: Highlander
Post Number: 566
Registered: 12-2001
| | Posted on Monday, August 09, 2004 - 7:18 am: |
|
Most SWR meters are calibrated using 5 or 10 watts at the most, this is where they will be the most accurate. I only put enough power in to deflect the needle on the meter to the swr set point. |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 115
Registered: 7-2004
| | Posted on Monday, August 09, 2004 - 12:48 pm: |
|
Bruce I'm not sure what your saying about the Ranger. I just got it, and if I need to can send it back for repair.
Highlander so if it's putting out 30 watts dead key. The SWR in the radio and the meter might be wrong? I was told not to really trust the meters on the radios, but it seems to get too hot after ralking on it even at low power for an hour with the locals. |
Bruce
Senior Member
Username: Bruce
Post Number: 1444
Registered: 9-2003
| | Posted on Monday, August 09, 2004 - 3:55 pm: |
|
NEVER use a built in meter get or borrow a known good one. If you STILL see a change put a low pass filter on BOTH radios and remeasure on the antenna side of the meter see if the swr gets closer..... high harmonic output wil show as increased SWR. |
Tech548
Moderator
Username: Tech548
Post Number: 212
Registered: 5-2004
| | Posted on Tuesday, August 10, 2004 - 2:49 am: |
|
Bob_p
Turn the power down to around 10-15 watts deadkey and see what you get then. That's about where your low-power setting should be set anyways otherwise the radio will start to heat up too quickly. Especially when using it on A/M. That radio will really kick butt on and live longer on SSB than it will on A/M.
And Bruce is right. Never trust the meter on your radio...especially the ones on any of the RCI 50s and 70s. They're a joke!
Look at it this way, if you can afford a high priced radio such as a 2970, then you certainly should be able to afford a good SWR meter.
"A good SWR meter and Dummyload ARE A MUST for ANY serious CB station".
Jeff
Tech548 |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 122
Registered: 7-2004
| | Posted on Tuesday, August 10, 2004 - 4:00 am: |
|
Thanks for the help guys, but I checked the antenna with a multi meter and it has a dead short. It ran to the far side of the meter as possible. So the Antenna is dust. I guess I should feel lucky I have any of my radio gear left. Bruce I have a few meters but began doubting the readings because they were showing under 2.0, and the radio was getting really hot. I have a week old Dosy TC-4001 and heard they showed SWR slightly higher than other meters, and in fact it seems to, but anyway I took the RCI off line and am going to order a new antenna asap.
Thanks again
Bob
-----------------------
Bob.
Just for future reference, some antennas do indeed show a dead short when putting a Volt/Ohm meter to them.
Jeff
Tech548 |
Pig040
Advanced Member
Username: Pig040
Post Number: 540
Registered: 7-2003
| | Posted on Tuesday, August 10, 2004 - 9:16 am: |
|
Bob,
I had a similar situation, my galaxy was showing 1.2 across the board, and the ranger was showing almost 2, dont know why. But I tuned the antenna with an mfj antenna gizmo, and it was right where it should have been so I left it alone, and never had a problem with either radio.
Rich |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 125
Registered: 7-2004
| | Posted on Tuesday, August 10, 2004 - 3:02 pm: |
|
Thanks Jeff I didn't know that. I just checked my 2 meterm Yagi and ground plane and they where fine. But something is wrong with that antenna because the radio even on low power gets extremely hot, and the SWR will not adjust when I turn the rings, or it will show an improvemnt then when I put it up it drops right back to where it was.
Anyway I sure hope it's the antenna, I can't imagine what else would cause the radio to get so hot you can't touch it after keying a few times checking the SWR. Unless there's a problem with the radio God forbid.
Thank as always Jeff really appreicate the knowledge
Bob |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 126
Registered: 7-2004
| | Posted on Tuesday, August 10, 2004 - 3:07 pm: |
|
Rich did the Ranger ever get so hot you couldn't hold your finger to it? That's whats happening on the RCI 2970DX on low power. Even the Cobra after awhile at 2.5 watts gets hot, so I've found a place that actually has the I-Max 2000 and put an order in. All I can do is hope thats the problem if it's not I'm not sure what to do. |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 129
Registered: 7-2004
| | Posted on Tuesday, August 10, 2004 - 6:25 pm: |
|
I just put a mag mount antenna outside and ran a coax to it and the radio still gets pretty warm to the touch even with a low SWR and on low power. Can someone tell me if this is normal I'm really lost here and don't know what to expect. But it doesn't seem right that the radio would get so warm after dead keying the radio at low power for a few minutes. If I hold it down for say 5 minutes it really get hot! I might be over reacting, but am totally unfamiliar with this type of radio.
Thanks for your patience
Bob |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 130
Registered: 7-2004
| | Posted on Tuesday, August 10, 2004 - 7:12 pm: |
|
Jeff by the way Copper tuned the radio and at the lowest setting it's around 30 watts. Like I said I might be over reacting, and by the way I use the radio exclusively for SSB except for Checking power settings SWR etc. The only thing I do not have is a dummy load. I have a PDC 600 that was getting old an Aries A-SWR1000 and of course the new Dosy TC-4001 |
Tech833
Moderator
Username: Tech833
Post Number: 806
Registered: 8-2002
| | Posted on Tuesday, August 10, 2004 - 10:04 pm: |
|
Bob,
Way too much here to get real specific, so I will just add my 2 cents and get out of the way...
SWR changes between radio of same power means that one of them is spurious. Retune it.
SWR changes with power level means reactance is not at zero. Retune antenna (or change coax length, another thread completely).
SWR changes between radio with same power and no spurs may be different coax lengths. use the SAME piece of coax between the two radios (no switch) and see if it still happens. You still have a J problem if you do.
A DC short on an antenna does not mean it is 'dust'. Many antennas have a DC ground. Do not panic.
Yes, your radio is supposed to get warm. But not hot. If you keep it keyed for 5 minutes at a time (if you are long winded), then it will get hot. |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 131
Registered: 7-2004
| | Posted on Tuesday, August 10, 2004 - 11:52 pm: |
|
Tech833 Thanks for the info. What caused me to get nervous was I was talking on low power SSB to a friend and after an hour or two the heat sink was too hot to hold my hand on. Then I checked the SWR and there was a difference between two radios with different power levels, and thought that maybe the RCI with a dead key at low power could be in danger at an SWR of 2.0.1 or so. Then I tried to tune the Antron and when I set the rings dead center the SWR dropped but there was a serious loss of power according to my PDC 600. I then took someones advice and retuned it to where it was and the SWR was off the scale. I cannot get the antenna to tune correctly anymore. I did achive near the original SWR, but thats with the rings all the way down. So I am replacing the antenna, but am concerned that the radio is getting too hot and maybe the antenna might be feeding back into the radio. |
Pig040
Advanced Member
Username: Pig040
Post Number: 544
Registered: 7-2003
| | Posted on Wednesday, August 11, 2004 - 10:04 am: |
|
Bob,
No the Ranger did not get hot, but it did read the higher swer, I think some kind of false reading was happening. What I do now is use the MFJ antenna anaylzer on an antenna, and just go with that. I have not had a problem with this method, and have run as high as 1500 watts power in the mobile.
Rich |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 135
Registered: 7-2004
| | Posted on Wednesday, August 11, 2004 - 10:24 am: |
|
Thanks Rich I know someone who has one, but getting ahold of them is another thing. Right now it really would be nice to have one so I could tell what the heck was going on with the set up.
Rich thanks again
Bob |
Pig040
Advanced Member
Username: Pig040
Post Number: 547
Registered: 7-2003
| | Posted on Thursday, August 12, 2004 - 10:16 am: |
|
Bob,
That meter is one great tool, I used it to make my homeade vertical, and have great swrs across the band, the same with the JoGunn beam.
Rich |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 147
Registered: 7-2004
| | Posted on Thursday, August 12, 2004 - 2:40 pm: |
|
Rich Thanks I ordered a Dosy TC-4001 when I ordered the radio, and now have it in line. It's funny the PDC shows higher power readings and slightly lower SWR readings. But the PDC wouldn't read an SWR at less than about 5 watts, so I thought it was about time to replace it. But the Dosy needs about the same to get a decent SWR deading too. Oh well the Dosy looks better, it doesn't make me feel as good when I'm watching the SSB power out put, but figure the Dosy being new is probably more accurate.
Hope to catch you on the air waves soon.
Bob |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 149
Registered: 7-2004
| | Posted on Thursday, August 12, 2004 - 4:32 pm: |
|
Oh I just figured out that you meant the antenna anylalizer. I wish I could afford one, but I don't think I would use it very much. I'm not that much of a tech. I just put the radio in line hook up the power supply put the power SWR meter in line ground it best I can and there ya go. But in the future it might be more useful if I decided to try building multi-band antenna for HF or something. From what I hear it's not really all that tough. I really thought antennas were pretty simple until I ran into the problems with the A-99.
Thanks for the info Rich
Bob |
