Base FNG with an SWR question

[Rok55]

Recently acquired a used Uniden 880 and a Uniden 980SSB. 880 came with a mag mount 52" stainless whip that reads over 3 SWR through an Astatic PDC2 meter using a 2' jumper of RG8 from the TX on both radios.

Purchased a used Wilson Silverload and mounted to the mag mount which at initial install tested good through onboard diagnostic on the 980 with 1.4 SWR (same result on 880). A few days later took the SWR meter out of the loop and went straight to the 980, antenna failed diagnostic and went over 3 SWR. Same response on 880. What gives? What am I missing?

It may be pertinent to know that the antenna is sitting on the floor inside a window of an upstairs room. Coax is run along the walls with no coils. Yes I understand that will not TX well for lack of ground plane, but believe I should be able to tune and get a decent SWR for RX until I can get a better antenna for my situation.
(Maco V58 is due to arrive tomorrow) .............

 

[338_MtRushmore]

It is interesting that you were able to get a low reading to begin with. Set it on something metal and give it a try.

Swr only pertains to tx. You can try to receive all day long with no ill effects to the radio.

 

[Rok55]

Thx, I do understand that SWR is TX only. Just removing the meter from the system shouldn't have made that kind of change.

 

[338_MtRushmore]

It shouldn't have been 1.4 to begin with. Coax length can do some strange things to swr reading on bad antenna installs. What was your reading on 1 and 40 before you removed the jumper?

 

[Rok55]

Why shouldn't it be 1.4? From what I've read that would actually be a fair SWR for a 5' Vertical GP Mag mount?

Discovered a bad connection at the PL259 on antenna coax. Clipped and replaced got me a 1.68 on Ch1 and 1.64 on Ch40 from Tx on the 880. Oddly it still fails on the 980. Beginning to feel as though the 980 has a problem.

Maco V58 showed up today so I'll get it assembled and tuned in the next few days and hopefully verify what's going on here.

 

[M0GVZ]

Thx, I do understand that SWR is TX only. Just removing the meter from the system shouldn't have made that kind of change.

Well with the setup you have you do actually have a ground plane....its your coax, your SWR meter, the rig, the power supply leads and even the wiring in the building. So as the coax is forming the missing ground plane when you change its length you change the tuning of the antenna system.