Re: [Drakelist] MS-4 Speaker
FYI, Referred to in the autotrade as 'Stonechip' or 'Underbody Schutz' still available in spray cans. 73 Max M0GHQ - Original Message - From: K9sqg To: 1oldle...@ix.netcom.com ; bob.lov...@sbcglobal.net Cc: drakelist@zerobeat.net Sent: Wednesday, April 17, 2013 8:39 PM Subject: Re: [Drakelist] MS-4 Speaker If one wants to lower the resonant frequency of a metal speaker enclosure, there used to be a product out that was available in a spray can, and it would form a thick, tar-like surface. It was sold in auto supply houses for coating wheel wells and car frames. 73, Evan, K9SQG ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] R4C Hum and audio transistor
I have a very nice R4C it had a hum with bad audio distortion so I decided to investigate, whilst taking it apart I noticed that if I touched the noise blanker the hum would alter, I removed the NB board and the hum was still there, I found eventually that the audio transistor had desoldered itself, do they really run that hot? so I resolded the wires, now the radio does not work anything like as well and has a high amount of white noise, has that audio transistor died and if so where do I get a new one, is there an equivalent for that power transistor? 73, Max M0GHQ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4C Hum and audio transistor
I must admit this receiver will probably benefit from the Sherwood audio board, however comparing both my R4C's one is perfect with no hum and very good audio whilst this one is shushy and has bad hum, maybe the main caps need replacing but when I couple another cap accross them no change so I am a little reluctant to ditch them quite yet. swapping the tubes between each made no difference either. It does do an odd thing though, gradually as it warms up the audio and signal gets worse until it is distorted and with a lot of white noise. When switched on, the hum is really bad immediately and does not go away. both receivers are 26000 serials within about 700 from each other. Ideas? 73 Max M0GHQ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] R4C problems
It has now decided not to work anymore, I was listening to it and gradually the white noise came up, the signal died and now the preselector is in the wrong place for each band ie the 40m band livens up around the 80m mark however there is no signal present, even the cal does not work anymore. I have not put a meter or scope around the radio yet but has anyone come across this behaviour before? I am beginning to realise why this radio is absolutely mint out of the box condx and the one that works faultlessly is a bit scruffy. 73 Max M0GHQ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] R4B noises
I have a nice R4B and after replacing all the caps except the main can, I still have a slightly raspy crackly noise when both RF and AF gain controls are fully open, is this normal? I just do not wish to chase something down that is not going to improve no matter how many bits I throw at it. I have swapped out all the tubes as well with no improvement. 73 Max M0GHQ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Crackle on R4-B
I have just got a new to me R4-B, it is a clean set unmodified in anyway, however it has an annoying crackle all the time, constant volume in the audio, I am sure it is the main cap but just to be sure, ideas? it is just low volume just like a commutator noise but in the background, it does alter volume with the volume controls but goes away on AM although there is a bit of hum detectable on AM , with the passband tuning control altered it sounds like running water, most strange, all this with the antenna shorted. I am assuming Hayseed is the best for the replacement main can capacitor. Anything else I might add/change while it is apart, Looking on the web there is an Italian that suggests some cap changes for better audio, has anyone done this, any good? Not looking to do any irreversable or damaging mods, I wanted it for casual Topband work. 73 Max M0GHQ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
