I’ve been off of CB for 20 years and I’m new here so please go easy on me.
I have a Uniden PC33 that I got eons ago and I recently took it out to use on a trip to SC.
Initial inspection: the power cord had to be replaced; TR-14 - 2SC1815 and C-103 - 0.001 uF Cap are missing from the board (not by my hands); coil L6 is spread apart slightly; the final is a 2SC2078 (not a 2SC2029 as indicated on the schematic); several components look like they need replacing do to age and I am sure the switches need a good cleaning. Solder joints look OK and no components are cut except those mentioned earlier.
I took some measurements using a CN 801 meter and a 100W 50 ohm dummy load: 4 watts dead key swinging to 5 watts on AVG setting & 4 watts swinging to 12 watts on the PEP setting using the 20 Watt scale on channel 20. Audio testing with a base antenna attached sounded good while monitoring on a different radio – no audio anomaly's heard. There was some splatter on 1 or 2 adjacent channels but I chalk that up to having both radios in close proximity while keying up (I did use 20dB of attenuation). The radio was on frequency – checked that with an MFJ 259B analyzer’s freq. counter.
On the trip: the PC33 was grounded to the vehicle’s interior; had an Astatic RD104E Road Devil power mic with a fresh 9V battery attached and was connected to a Wilson 1000 antenna using a magnetic mount (SWR was 1.5 on channel 20 according to the MFJ 259B analyzer). My first contact copied me, but said that I had a squeal. The mic gain slide switch was at 25%; I lowered the slide switch gradually with no change to the squeal; when I put the switch all the way down I was told my audio was very low. Fortunately I took along a backup radio – a Cobra 25 that I used with no complaints about squeals with the Road Devil attached.
Any ideas on what caused the squeal, the lack of TR14/C103, or a combination of things? There was no squeal when I originally tested the radio in my home so I’m baffled at why the squeal started in the mobile.
I have a Uniden PC33 that I got eons ago and I recently took it out to use on a trip to SC.
Initial inspection: the power cord had to be replaced; TR-14 - 2SC1815 and C-103 - 0.001 uF Cap are missing from the board (not by my hands); coil L6 is spread apart slightly; the final is a 2SC2078 (not a 2SC2029 as indicated on the schematic); several components look like they need replacing do to age and I am sure the switches need a good cleaning. Solder joints look OK and no components are cut except those mentioned earlier.
I took some measurements using a CN 801 meter and a 100W 50 ohm dummy load: 4 watts dead key swinging to 5 watts on AVG setting & 4 watts swinging to 12 watts on the PEP setting using the 20 Watt scale on channel 20. Audio testing with a base antenna attached sounded good while monitoring on a different radio – no audio anomaly's heard. There was some splatter on 1 or 2 adjacent channels but I chalk that up to having both radios in close proximity while keying up (I did use 20dB of attenuation). The radio was on frequency – checked that with an MFJ 259B analyzer’s freq. counter.
On the trip: the PC33 was grounded to the vehicle’s interior; had an Astatic RD104E Road Devil power mic with a fresh 9V battery attached and was connected to a Wilson 1000 antenna using a magnetic mount (SWR was 1.5 on channel 20 according to the MFJ 259B analyzer). My first contact copied me, but said that I had a squeal. The mic gain slide switch was at 25%; I lowered the slide switch gradually with no change to the squeal; when I put the switch all the way down I was told my audio was very low. Fortunately I took along a backup radio – a Cobra 25 that I used with no complaints about squeals with the Road Devil attached.
Any ideas on what caused the squeal, the lack of TR14/C103, or a combination of things? There was no squeal when I originally tested the radio in my home so I’m baffled at why the squeal started in the mobile.