I know it would be much higher in the AM brocast bands and Shortwave bands. Gain,but does any one have a clue how much RF gain does this tube have up in the FM frequency range. I know pentagrid converters can do the local osilating and mixing,but I was told they do have some RF On a tube tester have anything to do with how well the tube will perform up in the FM Band. I was guessing this was a really low serial number but not sure.Īnyways I would like to get this radio working like the day it sold in the Stores. I am guessing the B is the Version I have. Now I did notice my serial number had B001101 I had anothe question that there was a debate wether this radio was sold in 1946 or 1947. I am just wondering how well that circuit worked when it was first sold in 1946. That whole Circuit with the 6BE6 seem to be so touchy. It the trimmer cap on the left side on the gang caoacitor if you are looking from the back of the radio. Also the trimmer capacitor that for the rf has some affect on the oscilator frequency, I am having more problems with the lowerĮnd of the dial than the top. Now it seems everything below the radio station 95.1mhz drops out. Now it I hooked 2 separate wires up the the antenna terminals I was able to get 3 stations in weak.Īnyways I have 102.5 and 103.1 comming really close to the correct spot on the dial. I tried hooking up a folded FMĭipole antenna at 300 ohm impedance and all stations went gone. The original FM internal antenna is missing. I was able to get the dial fairly close,but I used a frequency checker to see what the local oscilator was outputting. It tune the oscilator frequency only a little bit. And I did notice that capacitor had very little effect Also I did not know about have the 2 separate thread rule, so thanks for that info.Īnyways Ok I will check the solder connections on the Mica cap. It actually sounds pretty nice, if/when it works. I haven't torn into it yet, other than to replace the e-caps so I know it won't burn my house down. Sometimes I pick up 106.7FM at the very bottom of the dial (pointer at 88). And on bad days, I can't even get any FM from the start. On an average day, it will receive FM after a good warm-up on AM, but after about 15 minutes of playing it goes "pop" and then nothing on FM any more. Sometimes on a nice dry day it will play for hours and receive FM all the way up to about 104 MHz. I have a 68R3, and it has all these problems too. It's a lot of work and it seems few people are successful at it. The only solution for this is to dismantle the coils and jury rig other trimmers. There are mica trimmer caps in the FM coils that leak and/or go open, and cause all kinds havoc with reception. ![]() This radio seems to have two common problems: 1) the 6BE6 as you noted, which apparently is solved by swapping 6BE6 tubes in and out till you find one that works, and 2) silver mica disease. If you do a google search for any of them here at ARC, you'll come up with some interesting reading: It seems that the ones that've probably been discussed here the most are the 68R1 and 68R3. The 68R1 was one of 4 radios that used the same chassis, the 68R1/2/3/4. I order a 5 brand new 6BE6 tubes hope for a better than 80 % emission ![]() Not sure if theis radio is 75 ohm input or 300 ohms. I tried 300 ohm twin lead external dipole antenna and the radio cut out I am listening to 102.5 mhz on the radio but I had to use 2 wires on the external antenna to get it to ocme in. Wow this 6BE6 in the front end seems to be what causing Has anyone every have these problems with this radio. It just seem like the radio has weak reception even after I tuned the RF circuits as well. high enough even for the 108 mhz and it did. I did hook a frequency counter up to make sure the tube would osc. Has anyonne worked on one of these before that could help me to get the dial calibrated with out the The tune the radio off frequency some and then sometime it cut out all to gether like the 6BE6 is not either It seem like the antenna messes up the osc circuit also. ![]() My RF trimer cap has to be tuned and then it end up putting 95.1 on about 97mhz When set correctly the one station I get strong will cut out. being at 100.8 Mhz which is the 10.7 Mhz above the 90mhz. ![]() I have the rider write up where it says to tune up the dial to 90Mhz and 106Mhz. Hi I have been workin on the RCA 68R1 radio.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |