another spectra problem
Moderator: Queue Moderator
-
asmitty0010
- Posts: 413
- Joined: Mon Sep 17, 2007 3:48 pm
another spectra problem
Got home today and the range on my spectra for receiving was cut in half. It still picks up but not like it should. What would cause this?!? Stations I was getting crystal clear are now clipping in and out..thats if they even break the squelch. I'm using an astro spectra right next to this unit off the same antenna and i'm recieving everything fine so its not an antenna issue. FYI no error codes and everything else seems to be normal. I have checked for leaking caps...nothing. - this is one of the newer spectras w/ black label.
Re: another spectra problem
You might check again. The leaky caps can't always be identified by visual means alone.
-
kc7gr
- Posts: 1031
- Joined: Wed Mar 13, 2002 4:00 pm
- What radios do you own?: Motorola, Icom, Sunair (HF).
Re: another spectra problem
I fully agree. If the caps are not positively known to have been changed out, do so! You lose nothing other than a bit of time and effort (and a few dollars for the caps), and you could end up saving your radio from a horrid fate.
Now, with that said... I've found, in times past, that loss of receiver sensitivity is caused more often by failed PIN diodes in the T/R switch circuits than leaky caps (although, in the A4, A5 and A7 radios, one of those suspect caps is in the PA and awfully close to the PIN diode section).
PIN diodes can be removed from circuit and tested with a multimeter, like any other common silicon diode. Their most common failures are shorted or open.
Happy troubleshooting.
Now, with that said... I've found, in times past, that loss of receiver sensitivity is caused more often by failed PIN diodes in the T/R switch circuits than leaky caps (although, in the A4, A5 and A7 radios, one of those suspect caps is in the PA and awfully close to the PIN diode section).
PIN diodes can be removed from circuit and tested with a multimeter, like any other common silicon diode. Their most common failures are shorted or open.
Happy troubleshooting.
Bruce Lane, KC7GR
"Raf tras spintern. Raf tras spoit."
Re: another spectra problem
"asmitty0010 " which Spectra radio are you talking about? Hi or Mid power, VHF or UHF?
On the mid power VHF Spectra, high VSWR from a bad or incorrect antenna can can cause damage to the RF amp in the receiver.
On the mid power VHF Spectra, high VSWR from a bad or incorrect antenna can can cause damage to the RF amp in the receiver.
Last edited by Will on Wed Jul 15, 2009 3:41 pm, edited 1 time in total.
-
asmitty0010
- Posts: 413
- Joined: Mon Sep 17, 2007 3:48 pm
Re: another spectra problem
It's a mid powered VHF spectra. I talked to a radio tech here and he is going to look at it. He seems to think a switching diode has failed possibly caused by static discharge on the antenna line input. He's gonna take a look at it and i'll let u know what happens.