• To anyone looking to acquire commercial radio programming software:

    Please do not make requests for copies of radio programming software which is sold (or was sold) by the manufacturer for any monetary value. All requests will be deleted and a forum infraction issued. Making a request such as this is attempting to engage in software piracy and this forum cannot be involved or associated with this activity. The same goes for any private transaction via Private Message. Even if you attempt to engage in this activity in PM's we will still enforce the forum rules. Your PM's are not private and the administration has the right to read them if there's a hint to criminal activity.

    If you are having trouble legally obtaining software please state so. We do not want any hurt feelings when your vague post is mistaken for a free request. It is YOUR responsibility to properly word your request.

    To obtain Motorola software see the Sticky in the Motorola forum.

    The various other vendors often permit their dealers to sell the software online (i.e., Kenwood). Please use Google or some other search engine to find a dealer that sells the software. Typically each series or individual radio requires its own software package. Often the Kenwood software is less than $100 so don't be a cheapskate; just purchase it.

    For M/A Com/Harris/GE, etc: there are two software packages that program all current and past radios. One package is for conventional programming and the other for trunked programming. The trunked package is in upwards of $2,500. The conventional package is more reasonable though is still several hundred dollars. The benefit is you do not need multiple versions for each radio (unlike Motorola).

    This is a large and very visible forum. We cannot jeopardize the ability to provide the RadioReference services by allowing this activity to occur. Please respect this.

Best Sounding Bases

Status
Not open for further replies.

Dawn

Member
Joined
Apr 5, 2003
Messages
284
Location
Pinecrest,Fl
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.
 

prcguy

Member
Joined
Jun 30, 2006
Messages
8,095
Location
So Cal - Richardson, TX - Tewksbury, MA
Up to the early 1980s, the best stock CB I ever tested in a lab was the CPI CP400. Quite an impressive radio on both transmit and receive. Its crystal filter alone cost more to produce than some entire radios.

I dont remember the exact specs but we had a lot of high end radios to test like Tram D201, Browning Golden Eagle MK something and so on. The CPI was way ahead of its time.
prcguy
 

JayMojave

Member
Joined
Dec 13, 2007
Messages
668
Location
Mojave Ca
Hello Space Man and All: Yes I'll bet they did. The very popular Lafayette Comstat series 23 and 25 came alive when the Turner + 2 Base Mic, or Turner M+2 Mic was installed. As did many other tube and transistor rigs of the time. These Lafayette Radios were big sellers all over the world.

Quit a few radios were "Strapped" (meaning a in series power resistor was "Strapped or bypassed" in the power supply to get more voltage to the finial RF Amplifier Tube, which usually only increased the RF power by a watt and in rare cases close to 2 watts. The term "Big Strapp" came from all this.


The General Radiotelephone Radios it would increase even more. But because the Modulators in these radios didn't have the extra power to modulate the finial RF Amp Tube with more power the Modulation percentage was reduced. I have fixed a few of these radios in my teen years but just removing the "Strapp" or bypass resistor across the series resistor in the power supply.

The General Radiotelephone MC11A and Super MC11A very popular radios, the Modulator used a German tube that had three tubes inside it was a ECLL800 (or now a replacement tube 6KH8) See:

www.thetubestore.com - 6KH8 / ECLL800 Audio Tubes

The General Radiotelephone Super MC12 then continued by the Skyhawk Co, replaced the ECLL800 with two 6BQ5 tubes as the modulator that was louder. And of course the tubes much easier to find.
So the General Radiotelephone MC12A was a Super MC 11A with a little more powerful Modulator.

Jay in the Mojave
 

Dawn

Member
Joined
Apr 5, 2003
Messages
284
Location
Pinecrest,Fl
I really appreciate the replies, but I was hoping to keep this about the receiver performance and not the transmit audio. Again, this topic is steeped in so much misinformation that people take for gospel based on what they've been told rather then the acutal performance of the radios.

I've never seen a CPI besides in a print ad or photo. I did have the privledge of corresponding back during the early 80's with one of the former owners or designers by the name of Roger IIRC that was then running another company. He apparently was making a big bet on CB going FM like the Brits. as the next stage of development after the boom wound down.
 

N8YX

Member
Joined
Dec 25, 2013
Messages
20
I really appreciate the replies, but I was hoping to keep this about the receiver performance and not the transmit audio. Again, this topic is steeped in so much misinformation that people take for gospel based on what they've been told rather then the acutal performance of the radios.

I've never seen a CPI besides in a print ad or photo. I did have the privledge of corresponding back during the early 80's with one of the former owners or designers by the name of Roger IIRC that was then running another company. He apparently was making a big bet on CB going FM like the Brits. as the next stage of development after the boom wound down.
CPI CP-2000/BC-2000 in my shack at the moment. If I do A/B receiver testing with that radio and one of my higher-end ham rigs, the CPI setup compares very favorably.

I've owned or worked on every "premium" CB (non-'export') rig in existence with the exception of the Stoner Pro-40 and the ARF-2001. All have made their way back out of the lineup. The CPI stuff remains.

There's a CP-2500 control head and a partially complete CP-2000 base in my pile 'o parts. One of these days I'm going to turn those into my own CP-2500 mobile...
 

prcguy

Member
Joined
Jun 30, 2006
Messages
8,095
Location
So Cal - Richardson, TX - Tewksbury, MA
I believe the owner or one of the owners of CPI was Robert Artigo and after CPI folded he started up other companies related to amateur radio.
prcguy


I really appreciate the replies, but I was hoping to keep this about the receiver performance and not the transmit audio. Again, this topic is steeped in so much misinformation that people take for gospel based on what they've been told rather then the acutal performance of the radios.

I've never seen a CPI besides in a print ad or photo. I did have the privledge of corresponding back during the early 80's with one of the former owners or designers by the name of Roger IIRC that was then running another company. He apparently was making a big bet on CB going FM like the Brits. as the next stage of development after the boom wound down.
 

Dawn

Member
Joined
Apr 5, 2003
Messages
284
Location
Pinecrest,Fl
This guy was selling FM modification kits and 10M conversion crystals for amateurs. He was also publishing a compilation of modifications and chip type glossary much like Lou Franklin. Apparently he was in some sort of negotiations with Palomar during that time and others to market a range of kits and amateur code practice tapes. I don't know if that ever happened, this was about '82-'83. I really was pretty much out of the CB repair since '76, but did do many conversions for local amateurs using his FM board. I also recall something about a kit he was planning to sell using one of the surplus hygain boards that were everywhere to make an inexpensive CB signal generator and deviation meter/FM modulator based on his amateur FM board.

OK, just dug though my stuff and the name was indeed Roger and he also signed "9CPI" after his name. The FM board was called the Spector FM IF strip. One of the schematics is marked R. Grant, so I would assume that was his last name. Ring any bells? Internet search turned up nothing.
 

prcguy

Member
Joined
Jun 30, 2006
Messages
8,095
Location
So Cal - Richardson, TX - Tewksbury, MA
Could you be talking about one of CPIs distributors? I remember our CPI rep flew his own plane around to meet with retailers and he handled a bunch of other things besides CPI radios.

I just dug (and dug and dug) out my original CPI brochure that shows the CP-300 and accys and it has the distributors info as Electro Marketing Associates out of Scottsdale, AZ. I believe the guy may have had a British accent and he loved to talk radios.
prcguy


This guy was selling FM modification kits and 10M conversion crystals for amateurs. He was also publishing a compilation of modifications and chip type glossary much like Lou Franklin. Apparently he was in some sort of negotiations with Palomar during that time and others to market a range of kits and amateur code practice tapes. I don't know if that ever happened, this was about '82-'83. I really was pretty much out of the CB repair since '76, but did do many conversions for local amateurs using his FM board. I also recall something about a kit he was planning to sell using one of the surplus hygain boards that were everywhere to make an inexpensive CB signal generator and deviation meter/FM modulator based on his amateur FM board.

OK, just dug though my stuff and the name was indeed Roger and he also signed "9CPI" after his name. The FM board was called the Spector FM IF strip. One of the schematics is marked R. Grant, so I would assume that was his last name. Ring any bells? Internet search turned up nothing.
 
Status
Not open for further replies.
Top