开云体育

Unloading the D104 cartridge makes more sense as the lower transmit passband width is extended.? For transceivers with a conventional 300 Hz to 2.4 kHz transmit bandwidth, the low-end response is

Those small rubber feet with embedded 6-32 studs are, as you note, used on the AC-4 Power Supply, and elsewhere. They are called out in the mounting options shown in the TR-4 series manuals as one of

I was there yesterday when you checked in and I didn't notice that your audio sounded tiny. I did the Heil element in a D104 carcass and had to add a matching transformer to get the impedance up.

FWIW, crystal and ceramic microphone elements look like capacitors. The load impedance forms a high pass filter with the capacitance. The higher the impedance the less the bass roll off. There is also

Yes, I am quite aware of the D-104 head characteristics. I'm the guy who posts the attached graph whenever this comes up. For the TR7 470K x 2 is an ideal load for the cartridge with plenty of voltage

I probably wouldn't have bothered with my TR7 - I would have just connected the D104 to that pin with the 470K resistor. This was in the mid-80's, and I wanted to hook it up to my TS-830S. I don't

I have never run any electronics in a D-104/T-UGxx. Just a 470K or higher resistor in series with the audio line. Still plenty of output to drive most anything and the cartridge is happy with its

You can find photos of the inside of a 7077 here: /g/DRAKE-RADIO/album?id=252836 It does have a small transformer in it to step up the voltage output to drive a TR7. No capacitors.

The 7077 is a dynamic mic, not a ceramic. I looked up 7075. Disregard my remarks. For more on the 7077 see: <https://www.wb4hfn.com/DRAKE/DrakeAcc/Drake%207077%20Microphone.pdf> -- Richard Knoppow Los

The 7075 is a ceramic element mic. Ceramic and crystal elements measure open circuit for DC. They look like capacitors. Your mic may be fine. -- Richard Knoppow Los Angeles WB6KBL SKCC 19998

I have a 7075; tried to get a resistance measurement that was not the PTT closure and every combination was open circuit. Don't have a schematic so I was fumbling in the dark. -- Craig/W8CS

It sounds like someone may have added a filter to the mic. Can you tell if the transformer is open? Is is actually a choke?

That sounds like a legit mod. The D-104 element has very high output and does not need amplification for most rigs but can benefit from a very high load impedance. -- Richard Knoppow Los Angeles

This came with my first TR7, which I bought in 2019 from a ham. The mic worked fine until today. It’s still a head-scratcher… Steve Wedge, W1ES Time flies like an arrow. Fruit flies like a banana.

I have a D-104 that I added circuitry to. A JFET source follower. No gain, but it presents an extremely high impedance to the mike element. Always gets me good reports. - Jerry, KF6VB

I bought the Drake mic with bad mic element. Had an extra Kenwood MC-50 laying around and put that element inside and get great audio reports. Good luck and 73. Tony N5DIM

Sounds like something a CBer might do to get more audio grunt. - Jerry, KF6VB

It is looking like I’ll need to do that. The current element fits but there are series capacitors and that tiny transformer. These components seem to be good (capacitors are dead-on). I was shocked

I put the Heil element in mine. Works great now. Larry - KB9VY Sent from [Proton Mail](https://proton.me/mail/home) for iOS

Hi, gang! I went on to the 7238 Drake Pre-net this afternoon and strange things were happening. I heard some noise in the speaker when the PTT was pressed and WB0IQK said that I sounded excessively