开云体育

Good morning. Late night in the shack and was listening to the bands with the B-line twins. Everything is working well with exception of the R4B on 80m. Generally I run the twins with the proper

Bob thank you for the assistance, cleaning up the potentiometer wiper and coil seems to have resolved the issue. Joe ki5o

I have no skin in this. Someone is selling faceplates for R-4A and R-4B receivers on eBay. Steve Wedge, W1ES/4 Time flies like an arrow. Fruit flies like a banana. Sent from [Proton

I should clarify the last post, now that I’m on my second cup of coffee. If the input SWR is below 2:1 across the band, I wouldn’t bother messing with it. My L7 has no trouble being driven to full

That’s great news, Howard! On the 6 “legacy” bands, the SWR should be roughly 2:1 or less. Honestly, there are only two ways it can change: an bad part or someone being in there before, trying

To add further to the mix, here is an archived thread from eHam forums on improving the 10 Meter input circuit:

Yup I'm familiar with the two safety switches on my L7's.? And my L7's would both be imports.as they have stock 10m band positions.?On another note did I see that RV75' s are fetching $1000.00US

Fellow Drake Enthusiasts, Two comments. First, unlike the L4B, the L7 has two (2) safety related devices. ?The first is the above chassis high voltage shorting mechanism, the other is a microswitch

I use and have used the MFJ series. It is an old one, but I have found them quite handy. David Assaf III W5XU, VP8RXU

Thanks guys for all the input on input coil adjustment. Ran the amp today on 40m and had a swr of 1.2:1 between amp and L7 at about 1500watts PEP output to flat swr into my dipole. Going to check

? Excellent thread thanks for all the good information. I am just completing refurbishing an L4 B and will be tuning it up. Your insight is much appreciated. Do you have a recommendation on an

Accepted---thanks K0UYA

Ooops...sorry Paul....I wrote that very poorly and didn't pick it up in the proofread! Actually, while nichrome parasitics WERE removed from that amp (and I made my own copies of the originals to

For the record? I have NO parasitic suppressors new or old for ANY amplifier. For the record. Apology forthcoming? Paul K0UYA

Howard: I'll add two comments to David's instructions for adjusting the input tuning on the L-7 1) Check out the L-4B instructions. They got that correct and it's the same procedure. 2) While I would

Howard: Please forgive me if this is a somewhat disjointed note as I am still in the hospital but with the promise I will be home today after 4 days here. The input circuit is to tune the input for

I was at the FDIM QRP forum and had hands on with this receiver. The video doesn’t do it justice. mike wb8vge

Great, thanks! --Ed, N3CW--

W4OP describes his receiver in this youtube video: https://www.youtube.com/watch?v=O077VLhmCD4 Bob/WB0AUQ

I bet the owner of PAR knows where that board design came from and would be willing to share. John k5mo