I just purchased a NOS Sears Roadtalker 40ch AM only radio Sears Model Number is 6138081 and 934.38081700 FCC CM-6000LA . It is seriously a fantastically built radio. I could not find a board number on it. It has a rf shielded pll/vfo that I have not taken off yet. I am hoping it is under that shield.
Since it was built in Japan I am guessing it was built by Cybernet but it does not look like my other SSB Cybernet’s at all. Some of the cap’s have a date code of 1977 on them. It looks like someone decided to copy a Cobra 29 but with better components. When did the Cobra 29 hit the market? I tried to Google that but could not find it. I know I have read that info before online before. The channel selector is built like a Brick Outhouse and the switches and pot’s are smooth and tight. I had forgotten how well things where built pre-1980’s.
The mic is still sealed in plastic and so are all the hardware pieces. It had $20 shipping so the total was $71 and you could not hope to find a NOS/NIB Cobra 29LTD for $71 shipped.
It keys 3 ¾ watts with very little swing. I am guessing the modulation is going to be the typical 60%.
I was surprised I thought it would have dual push-pull transistors for audio but no it has a audio IC. I could not see the number obviously but I am guessing it is going to be a TA7205P or something in that family.
2SC1951 driver and I think it was a 2SC1909 final not very powerful wattage wise but they both have really high min hfe values. I think one of them is a min 60hfe and the other is a min 100hfe very similar to how the Cobra 25/29 are set up. It has transformers for the audio. It has SWR/RF, NB, CB/PA etc…The meter still moves like new and there is no ageing to the paper.
The ch display has a huge voltage regulator hanging off it. I looked it up at the time and it is a 30V regulator I think at 3A which has to be over kill for a channel selector and display! Maybe there was a shortage of TO-220 voltage regulators in 1977 I am not sure I was only 4 years old at the time but sure seems like a bit much.
I was looking this stuff up on my phone at a 6 hour long track meet so if I get some things wrong I do apologize!
As is the rule it would seem for Cybernet everything that should be shielded is. If something needs to be heat sinked it is and if not than it is not. I still do not get though why anyone would design a board and have transistors floating in space when they could have easily designed them to all heat sink against the chassis. Especially the larger TO-220 type transistors they give that nice metal tab at the top with a hole in it for a reason and to not use it seems odd? Especially for related parts like the driver and final. How hard would it have been to put them right next to each other and share a heat sink?
This one is kind of far down my list of radio’s to re-cap since I have a Uniden PC78 XL AM only from the 1990’s that is AM only as well I need to re-cap and a 2 SSB radio’s to re-cap. I have to admit though I am curious to see how this radio turns out since she is built with such high quality parts. Every part of this radio the switches, pot’s wires, how thick the steel is on the cover’s all scream quality. The original price from Sears is on the box $79….LOL The warranty hang tag was still on the knob’s. LOL
I would love it if I could get 2 watt dead key modulating to 8 watts with 100% modulation. Since it is AM only when I do get around to re-capping it I will try to select cap’s that beef up the audio a bit. I am going to order a Sam’s Photo Fact for it Monday I think!
I am considering doing a 4 pin or 5 pin Uniden mic socket for it as well since at some point it will need a new mic and no one is making mic’s that style of 4 pin Din plug.
I love that they packaged all the filtering/choke coils in a gray shrink wrap. You know the ones people like to spread to get more watt’s on a meter!!
If you find one NOS or Mint I would not hesitate to buy it. Obviously price matter's but it looks to be at least as good if not better than the older Cobra 29's. Because I have not had a chance to take the RF shield off I do not know what PLL is in it or if it is easily modified. I am guessing it is not since I got it so reasonably. Usually if it one of the models with a 02A or 858 people are on them like fly's on poop or white on rice bidding up the price!
Oh and the chrome on the bezel is super thick and rich they must of put it on much heavier back then because it just looks denser and has a different look and feel to it.
Since it was built in Japan I am guessing it was built by Cybernet but it does not look like my other SSB Cybernet’s at all. Some of the cap’s have a date code of 1977 on them. It looks like someone decided to copy a Cobra 29 but with better components. When did the Cobra 29 hit the market? I tried to Google that but could not find it. I know I have read that info before online before. The channel selector is built like a Brick Outhouse and the switches and pot’s are smooth and tight. I had forgotten how well things where built pre-1980’s.
The mic is still sealed in plastic and so are all the hardware pieces. It had $20 shipping so the total was $71 and you could not hope to find a NOS/NIB Cobra 29LTD for $71 shipped.
It keys 3 ¾ watts with very little swing. I am guessing the modulation is going to be the typical 60%.
I was surprised I thought it would have dual push-pull transistors for audio but no it has a audio IC. I could not see the number obviously but I am guessing it is going to be a TA7205P or something in that family.
2SC1951 driver and I think it was a 2SC1909 final not very powerful wattage wise but they both have really high min hfe values. I think one of them is a min 60hfe and the other is a min 100hfe very similar to how the Cobra 25/29 are set up. It has transformers for the audio. It has SWR/RF, NB, CB/PA etc…The meter still moves like new and there is no ageing to the paper.
The ch display has a huge voltage regulator hanging off it. I looked it up at the time and it is a 30V regulator I think at 3A which has to be over kill for a channel selector and display! Maybe there was a shortage of TO-220 voltage regulators in 1977 I am not sure I was only 4 years old at the time but sure seems like a bit much.
I was looking this stuff up on my phone at a 6 hour long track meet so if I get some things wrong I do apologize!
As is the rule it would seem for Cybernet everything that should be shielded is. If something needs to be heat sinked it is and if not than it is not. I still do not get though why anyone would design a board and have transistors floating in space when they could have easily designed them to all heat sink against the chassis. Especially the larger TO-220 type transistors they give that nice metal tab at the top with a hole in it for a reason and to not use it seems odd? Especially for related parts like the driver and final. How hard would it have been to put them right next to each other and share a heat sink?
This one is kind of far down my list of radio’s to re-cap since I have a Uniden PC78 XL AM only from the 1990’s that is AM only as well I need to re-cap and a 2 SSB radio’s to re-cap. I have to admit though I am curious to see how this radio turns out since she is built with such high quality parts. Every part of this radio the switches, pot’s wires, how thick the steel is on the cover’s all scream quality. The original price from Sears is on the box $79….LOL The warranty hang tag was still on the knob’s. LOL
I would love it if I could get 2 watt dead key modulating to 8 watts with 100% modulation. Since it is AM only when I do get around to re-capping it I will try to select cap’s that beef up the audio a bit. I am going to order a Sam’s Photo Fact for it Monday I think!
I am considering doing a 4 pin or 5 pin Uniden mic socket for it as well since at some point it will need a new mic and no one is making mic’s that style of 4 pin Din plug.
I love that they packaged all the filtering/choke coils in a gray shrink wrap. You know the ones people like to spread to get more watt’s on a meter!!
If you find one NOS or Mint I would not hesitate to buy it. Obviously price matter's but it looks to be at least as good if not better than the older Cobra 29's. Because I have not had a chance to take the RF shield off I do not know what PLL is in it or if it is easily modified. I am guessing it is not since I got it so reasonably. Usually if it one of the models with a 02A or 858 people are on them like fly's on poop or white on rice bidding up the price!
Oh and the chrome on the bezel is super thick and rich they must of put it on much heavier back then because it just looks denser and has a different look and feel to it.
...runna pile-up on 6m SSB