swr on antenna

[Dr_DX]

Moonwalker6,

What was the result of your dummyload test? Since you are having rather severe problems, I would concentrate on getting the SWR set with your radio initially, because if you can't do that, then you won't get the amp to adjust either. If you take the amp out of line, does it help? What happens if you remove the grounding wire on the antenna? The antenna isn't going to cover 27.165 - 29.965 (2.8Mhz) without using a tuner. If you had to pick 1 freq. to tune your antenna to, what would it be?

 

[moonwalker61]

I don't have a dummy load test yet, I been looking for one on Ebay. Yes the amp is completely un-hooked & no change in SWR. Yes the ant. grounding wire is un-hooked & no change in SWR. If I pick a freq. it would be channel 20 which would be in the middle of channel freq. 1-40. And to the best of my knowledge would be 2700 MHZ. I don't have a freq. counter or dummy load or low pass filter YET anyway. right now with bare radio set at 4 watts, I'm getting 2 swr on 40 & 4 swr on ch.1. Can't lengthen ant. anymore than it is. With radio cranked up to 20 watts, SWR'S go out of sight like8-9 SWR'S. Thank you for helping me with this matter, I appreciate it. I've been looking at the FMJ. dummy loads on Ebay.

 

[BJ radionut]

This radio sounds like it's pumping out Harmonics.
When turned wide open VSWR should not change.
Therefore radio is transmitting on frequencies outside the CB band, thus giving you false readings.
Do you have another radio you can try on same antenna?
All the Best
Gary

PS: What make, and model # meter are you using to make your test with?

 

[moonwalker61]

Yep- tried another radio & got the same results. my meter is a Workman hp201s 5-1kw swr meter.

 

[Dr_DX]

MoonWalker6,

Just a quick question - when you change the watt output of the radio,are you re-calibrating the Workman (put bottom knob in "DIR" setting, key up on AM without modulation, and turn the top knob for full meter deflection)? Also, is the radio connected to the "trans" SO-239 in the back?

 

[Shadetree Mechanic]

Sounds like a bad coax connection.
I tore my station apart one time looking for a bad connection. Turned out to be a hokey 3 foot jumper. It looked fine on low power but with the smoke turned on, it was a no go.

 

[moonwalker61]

MoonWalker6,

Just a quick question - when you change the watt output of the radio,are you re-calibrating the Workman (put bottom knob in "DIR" setting, key up on AM without modulation, and turn the top knob for full meter deflection)? Also, is the radio connected to the "trans" SO-239 in the back?

 

[moonwalker61]

yes I re-calibrate every time I change the watt setting. & yes the workman is connected right. coax and jumpers are all brand new.RG213. the jumper is connected from ANT. on back of radio to TRANS on back of swr meter, and antenna coax is connected to ANT on back of swr meter.

 

[Dmans]

The dummy load at the antenna end would solve the coax and coax jumper question. Buy, build or borrow one.

Other than that I would seriously review the antenna assembly instructions and make absolutely sure they are followed to a "T".

(I am sure the instructions do not show the proper measurements for use on 27.205 but I am also sure there are threads on this forum that will put you right on the money with the correct measurements.)

Good Luck.

73's
David

 

[Shadetree Mechanic]

The only way to know for sure is to use the process of elimination.

Step one.
Verify that the radio is ok by trying it on a different antenna and coax. Try it at someone else's house. I know you tried a second radio but this step would rule out the radio completely so we can move to step two.

Step two.
Get another piece of coax even a short one and hook it to your radio and antenna. This will rule out the coax and connectors. Even if it is new it can still be defective.

Step three.
Try a different antenna with your radio and coax. A mobile antenna would work. Even take the coax through a window to a car in the driveway and use that antenna.

Hope this helps. Let us know what you find out.
Chris

 

[Dr_DX]

Do you have an ohm meter? If so you can check your coax and jumpers for shorts or opens. Make sure you unscrew it from the antenna first. Also, if your shorting wire has been disconnected on the antenna, then you should show "open" when checking for continuity on antenna's SO-239 between the center pin and the barrel.

 

[Dr_DX]

Here are a couple of cantenna style Dummy Loads:

BID:
https://www.ebay.com/itm/Heath-Cant...193137?hash=item4b655dcc31:g:gd4AAOSws-5c8syT

Buy:
https://www.ebay.com/itm/Heath-Cant...062387?hash=item5468b6c933:g:nxUAAOSwg-tcPfGK

Just get it and add 3 1/2 quarts of Mineral oil and you will be ready to go.

 

[moonwalker61]

Ok guys; the dummy load came in today, with a 3' jumper and D.L. on it from the radio Im getting 0 SWr. and with the D.L. on the end of the 50' coax, I'm getting 0 SWr. I ohm the antenna and got around 30 Ohms.So I know the radio is good & the coax is good. I'm starting to believe there is something wrong with the antenna. And about the radio throwing out weird freq. I cant tell without a freq. counter. can't seem to put my finger on the high SWr's.

 

[nomadradio]

Ah, "ohm" the antenna?

As in with the ohms scale on a mutlimeter?

No way that reading is right for any antenna I'm used to. A DC-current "ohms" reading is not at all related to the RF-impedance "ohms" on an antenna.

An antenna that's good should show either an open circuit or nearly zero, no more than one or two ohms with a DC measurement from a typical digital multimeter, or even an analog Volt-Ohm meter.

30 ohms on that kind of meter can't be right.

73

 

[Beetle]

You're not getting "0 SWr". You might have nearly zero reflected power, but reflected power and SWR are not the same thing.