it's insane that they put a switching mode power supply into a sensitive, top notch receiver. it's insane that the 3rd IF is so close in frequency as the switching frequency of the power supply. it's insane that the digital IF unit is not shielded at all. regarding the new big 150uF 400 v filter cap, just power it from 300 volts through a 10k limiting resistor for at least 12 hours, before putting it into the SMPS. It will reform nicely.
Yes, this RX has several design problems; disappointing for its price! But in those days (90ies) there were only very few such receivers on the market.
I watched this video ~3 months ago and just watched it again. I am considering to purchase a WJ HF-1000 and trying to get a feel for it. I already have several Ten Tec RX 340's in my arsenal of high performance receivers. Ten Tec worked with WJ on this project. WJ's HF 1000 and TT's RX 340 have some similarities. I see strong points for both and weak area's as well. One point I mentioned last time is the use of acetone to quickly get rid of flux and other chemicals on a PCB. I have been doing this since the early 1980's and never had a problem. Since acetone evaporates quickly it does not have time to cause problems with plastics. Additionally, I have never had any issues with silkscreen being lifted or smeared with acetone. I would never use it on front panels or plastics but on pcb's its great. For Front panels, the best product, by far, I have used is called Simple Green. All of the auto stores in the US carry it. I suppose you have similar auto stores in Germany. I dilute it 40/60 water/simple green. It quickly cleans old grime, dirt, cig/tobacco smoke and makes the panel beautiful. It is suppose to be safe enough to drink, though, I do not recommend this. QUESTION for you Sir. Now that you have worked with Drake TR7's and the HF-1000, do you have an opinion on which is better in terms of performance. I realize they are TOTALLY different in design but in general, what is your opinion? Thanks for your video. 73, Glenn WA4AOS DSM Labs
Dear Glenn, for my part i prefer the analog designs and the best receiver is the R7 because of it´s notchfilter, the preamp and one more IF selectivity. than the TR7. I have also the NRD535 which is compareable to the R7.
I too was amazed when I opened my somewhat similar TenTec RX340 receiver with all the "open space" inside (a retirement present to myself). I considered the WJ as well. Hopefully WJ had a more elegant memory backup battery solution than the RX-340 which needed a special battery that wasn't easy to source. Nice fix as usual Stefan! 73 - Dino KLØS
The WJ has a NVRAM Type DS1643-120, which is a very special IC with internal(!) Lithium battery. This battery is now nearly empty (RAM error indicated sometimes) and i try to fix it with a new NVRAM or i´ll open the sealed IC and swap the battery - maybe a new video in the future
@@dl7majstefan753 A CR2032 would be so much simpler! I have a couple of HAL Terminal Units that have the same issue and I'm going to have to source a couple of similar Dallas DS1220Y packages. One has to be careful, the first ones I purchased long ago from a "large U.S. supplier" were most certainly counterfeit (had to go straight to Dallas at the time to determine that). Good luck with a substitute!
Glad for you to have the chance to put your hands on a receiver of that range. I found very interesting the meter in double scale, S units and dbm. Nice touch. Also I found interesting your electronic load. What are your thoughts on it? Is it worth it? I noticed has two separate inputs. I was oriented on the Korad KEL103 but yours caught my attention now. Kind regards Diego
What is the power output of that supply? How much does this receiver eats? Mine came without PSU and I want to put a linear one in myself - I would not risk the noise created by a switching one.
Sorry but i don´t have the manual - gave it back to the owner. But you can download the manual here: watkins-johnson.terryo.org/documents/manuals/HF-1000-Intermediate-Maintenance-Manual.pdf and look for the output of the PS
I wonder if there is something wrong with the smps that caused the problem on several capacitors instead of the capacitors causing the problem. What do you think Stefan?
As i said in the video, the switching pulses are a heavy challenge for the electrolytics; so they are distroyed over the years. But there is nothing "wrong" with the SMPS, because the SMPS behaves as it is designed to work. These switching pulses are a general problem of ALL SMPSs.
DL7MAJ Stefan I have a vintage zenith Trans oceanic transistor shortwave receiver I want to restore it let me no ware I can get Russian germanium transistors ?
Hoe about putting a proper transformer with diodebridge stabilizer transistor and big elco's and throw that switching source in the bin instead of servicing it
