8
votes
Accepted
How do I put an RJ-45 connector on to repair a Kenwood MC-59 microphone cable?
Here's how to repair a Kenwood MC-59 microphone cable (ships with the TM-V71a, probably the 710, and a few LMR radios as well).
First, if you didn’t know already, behind the rubber boot at the end of ...
- 2,057
6
votes
Repairing a Tecsun PL-660
I signed up here just to reply to this great (the only one I could find on the internet) question/experience that helped me with an identical problem. I was so close to giving up when I read this ...
- 61
5
votes
Accepted
Iskra sst 2030 radio speaker plug
To me, this looks very much like a "DIN Lautsprecherstecker":
Positive is the small hole, negative the wide slot.
Loudspeaker, if I ask google, is zvočnik in Slovenian – so the "ZV" label makes ...
- 17.4k
5
votes
Repairing a Tecsun PL-660
Tecsun is very similar to Baofeng in that anybody selling them expects a certain number of DOAs and other failures. They already know that QA on those rigs is directly reflected in the price.
In the ...
- 2,097
5
votes
Can an oscilloscope be used as an RF voltmeter?
One of the functions of an oscilloscope is actually to measure RF volts, just make sure to use the x 10 function to minimize loading on the circuit you are measuring, and keep in mind that some high ...
- 3,739
5
votes
How to avoid acoustic feedback while fixing radios?
You could use a headset or earphones with the receiving radio, so the received audio goes straight into your ears instead of to the microphone of the transmitting radio. Or you could use an assistant ...
- 9,320
4
votes
Accepted
How can I replace the NiMH battery in an old RigExpert AA230 Antenna Analyzer?
With the battery case detached from the device, look at the side with the copper terminals. You should see several seams that can be exploited with a sufficiently thin shim. I carefully used a box ...
- 1,455
4
votes
How should coax be physically wired to a "stud" mag mount?
Generally on a stud mount the center conductor is connected to the threaded stud with a ring terminal, you put the bolt through the terminal, then through the hole in the mount, and screw the stud ...
- 252
4
votes
Accepted
Globar resistor repair or alternative(s)?
This is an Inrush Current Limiter (ICL). You can still get them today, but they look quite a bit different. See Digikey for a wide range of parts. Typically, these are used for reducing the inrush ...
- 1,931
4
votes
Accepted
Presumably working FT-8900R doesn't turn on. What can be a reason?
OK, I figured it out. Turned out a little FFC cable disconnected inside the panel during the shipping. After fixing this the radio worked flawlessly!
3
votes
Accepted
Identification of valve
Are you sure that you are correct in the comments about your pin 2 and pin 7? (The conventional numbering for these tubes is as in your drawing, so conventionally pins 8 and 5).
If you look very ...
- 311
3
votes
How do I replace the Li-ion battery in a Kenwood TM-741A?
I found the TM-741A service manual. As shown on page 106, the battery can be seen looking into the case from the front after the display panel is removed. Luckily, the spare batteries from my dive ...
- 7,912
3
votes
Iskra sst 2030 radio speaker plug
LEVI means LEFT
DESNI means RIGHT
ZV1 is speaker one
ZV2 is speaker two
S this radio has connections for two pairs of 4 ohm speakers. I guess LEFT ZV1 and RIGHT ZV1 are main speakers and ZV2 are ...
- 880
3
votes
Can an oscilloscope be used as an RF voltmeter?
Maybe.
If measuring a circuit output that expects a load impedance, such as a 50 Ohm coax or antenna, then to measure the RF voltage at that point with an oscilloscope, you should terminate that ...
- 13.6k
3
votes
How should coax be physically wired to a "stud" mag mount?
GodJihyo nailed it on this problem. There's definitely a piece missing. (The piece that the feed cable passes through.) The mount base should be shaped like a wedding cake with another 'layer' that'...
- 463
2
votes
Does the Yaesu FT-897D have a BIOS/firmware in FLASH memory that could get corrupted 15 years in storage? Is there a re-install procedure?
It might be the problem, but a number of other faults are much more likely, starting from issues with aging capacitors not having the same capacity that they use to, over dopant migration in power ...
- 17.4k
2
votes
Jennings variable vacuum capacitor
Now solved (!)
fact: the capacitor inner part is now totally at the out position - meaning minimum capacitance.
to increase to max capacitance the brass part (see picture) must be pressed in.
usually ...
- 57
2
votes
Accepted
How to handle old stuck tuning slugs?
You should never use a metal tool on powdered iron or ferrite tuning slugs, adjustment tools for them are usually some type of plastic. You should be able to find these online. The better the fit, the ...
- 252
2
votes
Where can I find a service manual for the TECSUN PL-660 to replace the failed circuit board flex cable myself?
Try this link and check if it is what you are searching for:
https://elektrotanya.com/tecsum_pl-660_schematic.pdf/download.html
Note: Google Safe Browsing deems this site as 'No unsafe content found'.
...
- 63
2
votes
Yaesu FT-817 Won't transmit Dig, SSB or CW
Menu option for ssb filter (38?) should be "off", if no filter.
- 27
2
votes
Intermittent receive on FT-990
I have to ask the obvious question: is the antenna tuned when you are trying to receive? Briefly transmitting may activate an automatic tuner.
Relay contacts sound like a reasonable hypothesis, ...
- 52.5k
2
votes
How to splice RG-174 coax?
At HF there are almost no limits on how bad your splice can be, as long as:
there's no short circuit
braid is connected to braid and inner to inner
You could even use a "chocolate block" connector :)...
- 12.2k
2
votes
How to identify the mic connection pins in Heathkit SB-102?
Referring to the circuit diagram for this set
www.nostalgickitscentral.com/heath/schematics/heathkit_schema_sb102.pdf
The mic connector has 2 pins and the grounded body as the 3 connections.
As you ...
- 311
2
votes
Does the Yaesu FT-897D have a BIOS/firmware in FLASH memory that could get corrupted 15 years in storage? Is there a re-install procedure?
I have this rig as well; consulting both the manual and the Yaesu product page (specifically, the "Files" tab), there is no mention of firmware updatability or download files.
Based on the ...
- 4,658
2
votes
Use of Yaesu FT-7800R External Speaker Jack Loss of Audio
I regret my loss of audio was due to cockpit error. I accidentally had the tone squelch engaged; I went back through the CTSS procedure in the manual; and reset everything without tone squelch engaged....
- 191
1
vote
Heathkit SB-102 Plate Current out of control
In response to tuning the finals and grid dip: I’ve tuned a lot of IF strips as a Navaids Tech. VORs and Tacans mostly. Ham later. The procedure was always to start at the first IF and work to the ...
1
vote
Heathkit SB-102 Plate Current out of control
The creap could be a bad capacitor or the circuit is over loaded due to excessive voltage on the plate. This sounds systematic of a component failure and requiring component isolation and L-C meters. ...
1
vote
How to splice RG-174 coax?
Hmm. I've done this many times. Would a magnifying headband and extra light help you? That's certainly helped me to do that. The same way as we would splice larger coax.
- 8,174
1
vote
Does anyone repair Flex radios other than Flex Radio?
I know this is old, but my friends recommend Troy Radio. They are an authorized FlexRadio shop and specialize in the 5000. You can reach them at:
Link: Troy Radio
Phone: 254-239-3893
Email: toby@...
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