Dawn
Member
Everybody has an opinion on this one. Traditionally since most radios were designed to a price point, it was rare that they put much thought into AM radios since there's really supposed to be a guard band between channels and co-channel interference from overmodulation wasn't supposed to be part of the problem. Front end selectivity has been further compromised in recent years by diode switching and intentional broadbanding for out of band mods that are anticipated. I don't know what if any advancements have been made with recent radios using varactor tuning on the front ends, but I would assume the 12-10 M radios use this and further adds to the intermodulation problems.
Trams that used mechanical filters and some designs that had steep sided, quality crystal filters like the older Hygains and SBE's had the good selectivity and to some degree some designs had better audio. Among the higher end SSB bases, AM was generally an afterthought. The radios had great crystal filters for SSB, but used a cheap ceramic murata filter for AM with audio tailored for SSB.
In the 40 channel days, few radios got accolades. For some reason, the courier bases and guardian units got great reviews which is puzzling because the boards were essentially the same as the early uniden based palomars, Simba SSB/2, and the TRC-457/8 and their mobile upd858 equivalents. A look at a schematic doesn't reveal much difference from detection to audio. Original Cobra 148's and some presidents and cobra bases have earned a similar distinction. Circuitry proves otherwise for reasons above. I can't think of any chassis in the 40 channel days that didn't use the cheap murata ceramics, half wave detectors, or any other enhancements in providing better AM recieve. I profess ignorance at Browning as I have never been in one. I never understood the supposed audioquality of the couriers over the rest that used essentially the same boards. The only difference could be the choice of speaker.
I really now nothing about the imports. I own the Optima and truthfully from a subjective experience untiil I get to evaluate it using instruments, the audio and AM selectivity on my home discone is sub par. They have added a filtering for SSB the other similar units don't have, but AM is nothing to write home about. There's many radios I know nothing about in the recent import radios such as the Saturns or the RCI's and don't know if they have concentrated on improved AM. If the Optima is supposed to be a refined version of the presidents and RCI, I sort of doubt it.
What are your nominations for great AM on current or classic radios in recieve? Any AM filter mods from any 3rd party vendors or full wave/am detector mods or audio sweetening? Some older crystal and 23 channel am radios had spectacular audio before price factors entered into the equation.
What do you recommend as the best AM radios with great receivers? My old R390,R71 with a mechanical filter and detector mod, Kenwood R5000 with AM filter upgrade and later R75 with filters and Kiwa mods put any stock cb to shame.
Trams that used mechanical filters and some designs that had steep sided, quality crystal filters like the older Hygains and SBE's had the good selectivity and to some degree some designs had better audio. Among the higher end SSB bases, AM was generally an afterthought. The radios had great crystal filters for SSB, but used a cheap ceramic murata filter for AM with audio tailored for SSB.
In the 40 channel days, few radios got accolades. For some reason, the courier bases and guardian units got great reviews which is puzzling because the boards were essentially the same as the early uniden based palomars, Simba SSB/2, and the TRC-457/8 and their mobile upd858 equivalents. A look at a schematic doesn't reveal much difference from detection to audio. Original Cobra 148's and some presidents and cobra bases have earned a similar distinction. Circuitry proves otherwise for reasons above. I can't think of any chassis in the 40 channel days that didn't use the cheap murata ceramics, half wave detectors, or any other enhancements in providing better AM recieve. I profess ignorance at Browning as I have never been in one. I never understood the supposed audioquality of the couriers over the rest that used essentially the same boards. The only difference could be the choice of speaker.
I really now nothing about the imports. I own the Optima and truthfully from a subjective experience untiil I get to evaluate it using instruments, the audio and AM selectivity on my home discone is sub par. They have added a filtering for SSB the other similar units don't have, but AM is nothing to write home about. There's many radios I know nothing about in the recent import radios such as the Saturns or the RCI's and don't know if they have concentrated on improved AM. If the Optima is supposed to be a refined version of the presidents and RCI, I sort of doubt it.
What are your nominations for great AM on current or classic radios in recieve? Any AM filter mods from any 3rd party vendors or full wave/am detector mods or audio sweetening? Some older crystal and 23 channel am radios had spectacular audio before price factors entered into the equation.
What do you recommend as the best AM radios with great receivers? My old R390,R71 with a mechanical filter and detector mod, Kenwood R5000 with AM filter upgrade and later R75 with filters and Kiwa mods put any stock cb to shame.
