开云体育

Why not get some volunteers to start it up on 20? All we need are a few people willing to take turns being NCS. The harder part will be to find the right time and frequency, since there are likely

I would first check really carefully...with a loupe or magnifying glass, and a STRONG light to see if the existing knob is not already split perhaps. As far as the control itself...I would avoid spray

Rob, Yes I completely rebuilt the supply adding a 7812 regulator board which are dirt cheap on Amazon and elsewhere. I also added an LM380 audio board. again, dirt cheap, and everything runs from

Lionel, Unfortunately the glass to metal pin breakage was a problem with Network Sciences pins. The best hermetic pins were filters made by Piezo Technology. Rob, NC0B Sent: Tuesday, March 21, 2023

Doug, Yes it had to do with reducing audio hum. The whole power supply was poorly designed from day one with too much ripple in the 150 volt, -70 volt and 14 volt supplies. In this case I think it

For a temporary fix, what you suggest is OK. Others have had success with WD-40 in this application. If it were MY receiver, I would remove the switch, disassemble the bushing/shaft assembly,

I remember the Drake swap net on 75 meters.? I was a new ham in the late 80s and always wanted a Drake C line. WZ8O, now W8NS, Don, put out his phone number and said he had one for sale. I called him

Gary, Dave, John, Thanks for the replies! I removed the knob this afternoon and it is in good shape. It looks like the set screw presses against a fiber like bushing that surrounds the shaft and this

No problem - it was just a suggestion since I would like to be able to check in with my Twins. I will keep looking for better band conditions in the rising sunspot cycle. - Steve? W7SJT "Always look

We tried a 20 meter net many years ago and it never worked out. Very limited check-ins.? We also had a 75m swap net and had to disband that some years ago due to lack of participation. 73's, Mark,

The performance of ceramic caps depends on the exact type of material.? npo type are very good ,? it is the "hi k" type that have problems.? Temperature compensating caps have charities similar to

In comparing early and later R4C power supply schematics, a capacitor (C201) was added going from the output of the low voltage diodes to the high end of the filament string. It is listed as 20uf

Ceramic capacitors are bottom rung devices, with differing temperature coefficients depending on type (NPO being the best for routine cooling and bypassing applications). They do not fare well at low

Hi Bill, I use Mylar capacitors. Leakage and Q, but I suppose you could try ceramic. Rob, NC0B

I don't see any mention as to what type of capacitors to use. The reason I ask is I don't know why Drake used large tubular capacitors in their design. Is there any reason ceramic capacitors can't be

Hi Rob, It is Network Sciences Date Code (?) 7905 Thanks Lionel

One caution! If the knob is loose, please do NOT overtighten the set screw. This will surely result in the knob being stripped or split. If it's loose because the shaft is hard to turn, remove the

A normal selector switch. Is your knob set screw loose? ....Dave

That knob should most certainly operate with a click at each position, allowing reception of AM, USB and LSB/CW. There are two possibilities. One is simple, that the set screw for the knob is loose. I

Hello everyone, Last summer I picked up a 2-C to go with my 2-NT. I have been using it for CW without any troubles. I tried to listen to some SSB signals tonight and I found a problem... I cannot tune